Every problem in the chapter beside the book’s answer, a chapter at a time as you scroll.

Chapter 2: Equations and Inequalities

310 problems · 36 figures

Try It #1 §2.1 source ↗

Construct a table and graph the equation by plotting points: y= 1 2 x+2.

Answer

x y= 1 2 x+2 ( x,y )
−2 y= 1 2 (−2)+ 2= 1 ( −2,1 )
−1 y= 1 2 (−1)+ 2= 3 2 ( −1, 3 2 )
0 y= 1 2 ( 0 )+2=2 ( 0,2 )
1 y= 1 2 (1)+ 2= 5 2 ( 1, 5 2 )
2 y= 1 2 ( 2 )+2=3 ( 2,3 )
This is an image of a graph on an x, y coordinate plane. The x and y-axis range from negative 5 to 5. A line passes through the points (-2, 1); (-1, 3/2); (0, 2); (1, 5/2); and (2, 3).

Try It #2 §2.1 source ↗

Find the intercepts of the equation and sketch the graph: y=− 3 4 x+3.

Answer

x-intercept is ( 4,0 ); y-intercept is ( 0,3 ).

This is an image of a line graph on an x, y coordinate plane. The x and y axes range from negative 4 to 6. The function y = -3x/4 + 3 is plotted.

Try It #3 §2.1 source ↗

Find the distance between two points: ( 1,4 ) and ( 11,9 ).

Answer

125 =5 5

Try It #4 §2.1 source ↗

Find the midpoint of the line segment with endpoints ( −2,−1 ) and ( −8,6 ).

Answer

( −5, 5 2 )

2.1-1 §2.1 source ↗

Is it possible for a point plotted in the Cartesian coordinate system to not lie in one of the four quadrants? Explain.

Answer

Answers may vary. Yes. It is possible for a point to be on the x-axis or on the y-axis and therefore is considered to NOT be in one of the quadrants.

2.1-3 §2.1 source ↗

Describe in your own words what the y-intercept of a graph is.

Answer

The y-intercept is the point where the graph crosses the y-axis.

2.1-5 §2.1 source ↗

For each of the following exercises, find the x-intercept and the y-intercept without graphing. Write the coordinates of each intercept.

y=−3x+6

Answer

The x-intercept is ( 2,0 ) and the y-intercept is ( 0,6 ).

2.1-7 §2.1 source ↗

For each of the following exercises, find the x-intercept and the y-intercept without graphing. Write the coordinates of each intercept.

3x−2y=6

Answer

The x-intercept is ( 2,0 ) and the y-intercept is ( 0,−3 ).

2.1-9 §2.1 source ↗

For each of the following exercises, find the x-intercept and the y-intercept without graphing. Write the coordinates of each intercept.

3x+8y=9

Answer

The x-intercept is ( 3,0 ) and the y-intercept is ( 0, 9 8 ).

2.1-11 §2.1 source ↗

For each of the following exercises, solve the equation for y in terms of x.

4x+2y=8

Answer

y=4−2x

2.1-13 §2.1 source ↗

For each of the following exercises, solve the equation for y in terms of x.

2x=5−3y

Answer

y= 5−2x 3

2.1-15 §2.1 source ↗

For each of the following exercises, solve the equation for y in terms of x.

5y+4=10x

Answer

y=2x− 4 5

2.1-17 §2.1 source ↗

For each of the following exercises, find the distance between the two points. Simplify your answers, and write the exact answer in simplest radical form for irrational answers.

(−4,1) and (3,−4)

Answer

d= 74

2.1-19 §2.1 source ↗

For each of the following exercises, find the distance between the two points. Simplify your answers, and write the exact answer in simplest radical form for irrational answers.

(5,0) and (5,6)

Answer

d= 36 =6

2.1-21 §2.1 source ↗

For each of the following exercises, find the distance between the two points. Simplify your answers, and write the exact answer in simplest radical form for irrational answers.

Find the distance between the two points given using your calculator, and round your answer to the nearest hundredth.

(19,12) and (41,71)

Answer

d≈62.97

2.1-23 §2.1 source ↗

For each of the following exercises, find the coordinates of the midpoint of the line segment that joins the two given points.

(−1,1) and (7,−4)

Answer

( 3, −3 2 )

2.1-25 §2.1 source ↗

For each of the following exercises, find the coordinates of the midpoint of the line segment that joins the two given points.

(0,7) and (4,−9)

Answer

( 2,−1 )

2.1-27 §2.1 source ↗

For each of the following exercises, identify the information requested.

What are the coordinates of the origin?

Answer

( 0,0 )

2.1-29 §2.1 source ↗

For each of the following exercises, identify the information requested.

If a point is located on the x-axis, what is the y-coordinate?

Answer

y=0

2.1-31 §2.1 source ↗

For each of the following exercises, plot the three points on the given coordinate plane. State whether the three points you plotted appear to be collinear (on the same line).

(−1,2)(0,4)(2,1)

This is an image of a blank x, y coordinate plane with the x and y axes ranging from negative 5 to 5.

Answer


This is an image of an x, y coordinate plane with the x and y axes ranging from negative 5 to 5. The points (0,4); (-1,2) and (2,1) are plotted and labeled.

not collinear

2.1-33 §2.1 source ↗

For each of the following exercises, plot the three points on the given coordinate plane. State whether the three points you plotted appear to be collinear (on the same line).

Name the coordinates of the points graphed.

This is an image of an x, y coordinate plane where the x and y-axis range from negative 5 to 5. Three points are plotted: A, B, and C.

Answer

A: (−3,2), B: (1,3), C: (4,0)

2.1-35 §2.1 source ↗

For each of the following exercises, construct a table and graph the equation by plotting at least three points.

y= 1 3 x+2

Answer

x y
−3 1
0 2
3 3
6 4
This is an image of an x, y coordinate plane with the x and y axes ranging from negative 10 to 10. The points (-3, 1); (0, 2); (3, 3) and (6, 4) are plotted and labeled. A line runs through all these points.

2.1-37 §2.1 source ↗

For each of the following exercises, construct a table and graph the equation by plotting at least three points.

2y=x+3

Answer

x y
–3 0
0 1.5
3 3
This is an image of an x, y coordinate plane with the x and y axes ranging from negative 10 to 10. The points (-3, 0); (0, 1.5) and (3, 3) are plotted and labeled. A line runs through all of these points.

2.1-39 §2.1 source ↗

For each of the following exercises, find and plot the x- and y-intercepts, and graph the straight line based on those two points.

x−2y=8

Answer

This is an image of an x, y coordinate plane with the x and y axes ranging from negative 10 to 10. The points (8, 0) and (0, -4) are plotted and labeled. A line runs through both of these points.

2.1-41 §2.1 source ↗

For each of the following exercises, find and plot the x- and y-intercepts, and graph the straight line based on those two points.

3y=−2x+6

Answer

This is an image of an x, y coordinate plane with the x and y axes ranging from negative 10 to 10. The points (0, 2) and (3, 0) are plotted and labeled. A line runs through both of these points.

2.1-43 §2.1 source ↗

For each of the following exercises, use the graph in the figure below.

This is an image of an x, y coordinate plane with the x and y axes ranging from negative 5 to 5. The points (-3, 4) and (5, 2) are plotted. A line connects these two points.

Find the distance between the two endpoints using the distance formula. Round to three decimal places.

Answer

d=8.246

2.1-45 §2.1 source ↗

For each of the following exercises, use the graph in the figure below.

This is an image of an x, y coordinate plane with the x and y axes ranging from negative 5 to 5. The points (-3, 4) and (5, 2) are plotted. A line connects these two points.

Find the distance that ( −3,4 ) is from the origin.

Answer

d=5

2.1-47 §2.1 source ↗

For each of the following exercises, use the graph in the figure below.

This is an image of an x, y coordinate plane with the x and y axes ranging from negative 5 to 5. The points (-3, 4) and (5, 2) are plotted. A line connects these two points.

Which point is closer to the origin?

Answer

( −3,4 )

2.1-49 §2.1 source ↗

For the following exercises, use your graphing calculator to input the linear graphs in the Y= graph menu.

After graphing it, use the 2nd CALC button and 1:value button, hit enter. At the lower part of the screen you will see “x=” and a blinking cursor. You may enter any number for x and it will display the y value for any x value you input. Use this and plug in x = 0, thus finding the y-intercept, for each of the following graphs.

Y 1 = 3x−8 4

Answer

x= 0        y= −2

2.1-51 §2.1 source ↗

For the following exercises, use your graphing calculator to input the linear graphs in the Y= graph menu.

After graphing it, use the 2nd CALC button and 2:zero button, hit ENTER. At the lower part of the screen you will see “left bound?” and a blinking cursor on the graph of the line. Move this cursor to the left of the x-intercept, hit ENTER. Now it says “right bound?” Move the cursor to the right of the x-intercept, hit ENTER. Now it says “guess?” Move your cursor to the left somewhere in between the left and right bound near the x-intercept. Hit ENTER. At the bottom of your screen it will display the coordinates of the x-intercept or the “zero” to the y-value. Use this to find the x-intercept.

Note: With linear/straight line functions the zero is not really a “guess,” but it is necessary to enter a “guess” so it will search and find the exact x-intercept between your right and left boundaries. With other types of functions (more than one x-intercept), they may be irrational numbers so “guess” is more appropriate to give it the correct limits to find a very close approximation between the left and right boundaries.

Y 1 =−8x+6

Answer

x=0.75y=0

2.1-53 §2.1 source ↗

For the following exercises, use your graphing calculator to input the linear graphs in the Y= graph menu.

After graphing it, use the 2nd CALC button and 2:zero button, hit ENTER. At the lower part of the screen you will see “left bound?” and a blinking cursor on the graph of the line. Move this cursor to the left of the x-intercept, hit ENTER. Now it says “right bound?” Move the cursor to the right of the x-intercept, hit ENTER. Now it says “guess?” Move your cursor to the left somewhere in between the left and right bound near the x-intercept. Hit ENTER. At the bottom of your screen it will display the coordinates of the x-intercept or the “zero” to the y-value. Use this to find the x-intercept.

Note: With linear/straight line functions the zero is not really a “guess,” but it is necessary to enter a “guess” so it will search and find the exact x-intercept between your right and left boundaries. With other types of functions (more than one x-intercept), they may be irrational numbers so “guess” is more appropriate to give it the correct limits to find a very close approximation between the left and right boundaries.

Y 1 = 3x+5 4 Round your answer to the nearest thousandth.

Answer

x=−1.667y=0

2.1-55 §2.1 source ↗

For the following exercises, use your graphing calculator to input the linear graphs in the Y= graph menu.

After graphing it, use the 2nd CALC button and 2:zero button, hit ENTER. At the lower part of the screen you will see “left bound?” and a blinking cursor on the graph of the line. Move this cursor to the left of the x-intercept, hit ENTER. Now it says “right bound?” Move the cursor to the right of the x-intercept, hit ENTER. Now it says “guess?” Move your cursor to the left somewhere in between the left and right bound near the x-intercept. Hit ENTER. At the bottom of your screen it will display the coordinates of the x-intercept or the “zero” to the y-value. Use this to find the x-intercept.

Note: With linear/straight line functions the zero is not really a “guess,” but it is necessary to enter a “guess” so it will search and find the exact x-intercept between your right and left boundaries. With other types of functions (more than one x-intercept), they may be irrational numbers so “guess” is more appropriate to give it the correct limits to find a very close approximation between the left and right boundaries.

If the road was made in the previous exercise, how much shorter would the person’s one-way trip be every day?

Answer

15− 11.2= 3.8mi shorter

2.1-57 §2.1 source ↗

For the following exercises, use your graphing calculator to input the linear graphs in the Y= graph menu.

After graphing it, use the 2nd CALC button and 2:zero button, hit ENTER. At the lower part of the screen you will see “left bound?” and a blinking cursor on the graph of the line. Move this cursor to the left of the x-intercept, hit ENTER. Now it says “right bound?” Move the cursor to the right of the x-intercept, hit ENTER. Now it says “guess?” Move your cursor to the left somewhere in between the left and right bound near the x-intercept. Hit ENTER. At the bottom of your screen it will display the coordinates of the x-intercept or the “zero” to the y-value. Use this to find the x-intercept.

Note: With linear/straight line functions the zero is not really a “guess,” but it is necessary to enter a “guess” so it will search and find the exact x-intercept between your right and left boundaries. With other types of functions (more than one x-intercept), they may be irrational numbers so “guess” is more appropriate to give it the correct limits to find a very close approximation between the left and right boundaries.

After finding the two midpoints in the previous exercise, find the distance between the two midpoints to the nearest thousandth.

Answer

6.042

2.1-59 §2.1 source ↗

For the following exercises, use your graphing calculator to input the linear graphs in the Y= graph menu.

After graphing it, use the 2nd CALC button and 2:zero button, hit ENTER. At the lower part of the screen you will see “left bound?” and a blinking cursor on the graph of the line. Move this cursor to the left of the x-intercept, hit ENTER. Now it says “right bound?” Move the cursor to the right of the x-intercept, hit ENTER. Now it says “guess?” Move your cursor to the left somewhere in between the left and right bound near the x-intercept. Hit ENTER. At the bottom of your screen it will display the coordinates of the x-intercept or the “zero” to the y-value. Use this to find the x-intercept.

Note: With linear/straight line functions the zero is not really a “guess,” but it is necessary to enter a “guess” so it will search and find the exact x-intercept between your right and left boundaries. With other types of functions (more than one x-intercept), they may be irrational numbers so “guess” is more appropriate to give it the correct limits to find a very close approximation between the left and right boundaries.

In the previous exercise, find the coordinates of the midpoint for each diagonal.

Answer

Midpoint of each diagonal is the same point (2,2). Note this is a characteristic of rectangles, but not other quadrilaterals.

2.1-61 §2.1 source ↗

For the following exercises, use your graphing calculator to input the linear graphs in the Y= graph menu.

After graphing it, use the 2nd CALC button and 2:zero button, hit ENTER. At the lower part of the screen you will see “left bound?” and a blinking cursor on the graph of the line. Move this cursor to the left of the x-intercept, hit ENTER. Now it says “right bound?” Move the cursor to the right of the x-intercept, hit ENTER. Now it says “guess?” Move your cursor to the left somewhere in between the left and right bound near the x-intercept. Hit ENTER. At the bottom of your screen it will display the coordinates of the x-intercept or the “zero” to the y-value. Use this to find the x-intercept.

Note: With linear/straight line functions the zero is not really a “guess,” but it is necessary to enter a “guess” so it will search and find the exact x-intercept between your right and left boundaries. With other types of functions (more than one x-intercept), they may be irrational numbers so “guess” is more appropriate to give it the correct limits to find a very close approximation between the left and right boundaries.

If San Jose’s coordinates are (76,–12), where the coordinates represent miles, find the distance between San Jose and San Francisco to the nearest mile.

Answer

37mi

2.1-63 §2.1 source ↗

For the following exercises, use your graphing calculator to input the linear graphs in the Y= graph menu.

After graphing it, use the 2nd CALC button and 2:zero button, hit ENTER. At the lower part of the screen you will see “left bound?” and a blinking cursor on the graph of the line. Move this cursor to the left of the x-intercept, hit ENTER. Now it says “right bound?” Move the cursor to the right of the x-intercept, hit ENTER. Now it says “guess?” Move your cursor to the left somewhere in between the left and right bound near the x-intercept. Hit ENTER. At the bottom of your screen it will display the coordinates of the x-intercept or the “zero” to the y-value. Use this to find the x-intercept.

Note: With linear/straight line functions the zero is not really a “guess,” but it is necessary to enter a “guess” so it will search and find the exact x-intercept between your right and left boundaries. With other types of functions (more than one x-intercept), they may be irrational numbers so “guess” is more appropriate to give it the correct limits to find a very close approximation between the left and right boundaries.

A person on the top of a building wants to have a guy wire extend to a point on the ground 20 ft from the building. To the nearest foot, how long will the wire have to be if the building is 50 ft tall?

A right triangle with its bottom left point sitting on the point (0,0). The upper right hand corner is labeled (20,50). The base has a length of 20 units and the triangle has a height of 50 units.

Answer

54 ft

Try It #1 §2.2 source ↗

Solve the linear equation in one variable: 2x+1=−9.

Answer

x=−5

Try It #2 §2.2 source ↗

Solve the equation in one variable: −2(3x−1)+ x= 14− x.

Answer

x=−3

Try It #3 §2.2 source ↗

Solve the rational equation: 2 3x = 1 4 − 1 6x .

Answer

x= 10 3

Try It #4 §2.2 source ↗

Solve the rational equation: − 5 2x + 3 4x = − 7 4 .

Answer

x=1

Try It #5 §2.2 source ↗

Solve −3 2x+1 = 4 3x+1 . State the excluded values.

Answer

x=− 7 17 . Excluded values are x=− 1 2 and x=− 1 3 .

Try It #6 §2.2 source ↗

Solve the rational equation: 2 x−2 + 1 x+1 = 1 x 2 −x−2 .

Answer

x= 1 3

Try It #7 §2.2 source ↗

Find the slope of the line that passes through the points ( −2,6 ) and ( 1,4 ).

Answer

m=− 2 3

Try It #8 §2.2 source ↗

Given m=4, find the equation of the line in slope-intercept form passing through the point ( 2,5 ).

Answer

y=4x−3

Try It #9 §2.2 source ↗

Find the equation of the line in standard form with slope m=− 1 3 and passing through the point ( 1, 1 3 ).

Answer

x+3y=2

Try It #10 §2.2 source ↗

Find the equation of the line passing through ( −5,2 ) and ( 2,2 ).

Answer

Horizontal line: y=2

Try It #11 §2.2 source ↗

Graph the two lines and determine whether they are parallel, perpendicular, or neither: 2y−x=10 and 2y=x+4.

Answer

Parallel lines: equations are written in slope-intercept form.

Coordinate plane with the x-axis ranging from negative 5 to 5 and the y-axis ranging from negative 1 to 6. Two functions are graphed on the same plot: y = x/2 plus 5 and y = x/2 plus 2. The lines do not cross.

Try It #12 §2.2 source ↗

Find the equation of the line parallel to 5x=7+y and passing through the point ( −1,−2 ).

Answer

y=5x+3

2.2-1 §2.2 source ↗

What does it mean when we say that two lines are parallel?

Answer

It means they have the same slope.

2.2-3 §2.2 source ↗

How do we recognize when an equation, for example y=4x+3, will be a straight line (linear) when graphed?

Answer

The exponent of the x variable is 1. It is called a first-degree equation.

2.2-5 §2.2 source ↗

When solving the following equation:

2 x−5 = 4 x+1

explain why we must exclude x=5 and x=−1 as possible solutions from the solution set.

Answer

If we insert either value into the equation, they make an expression in the equation undefined (zero in the denominator).

2.2-7 §2.2 source ↗

For the following exercises, solve the equation for x.

4x−3=5

Answer

x=2

2.2-9 §2.2 source ↗

For the following exercises, solve the equation for x.

12− 5(x+3)= 2x− 5

Answer

x= 2 7

2.2-11 §2.2 source ↗

For the following exercises, solve the equation for x.

x 3 − 3 4 = 2x+3 12

Answer

x=6

2.2-13 §2.2 source ↗

For the following exercises, solve the equation for x.

3(2x−1)+ x= 5x+ 3

Answer

x=3

2.2-15 §2.2 source ↗

For the following exercises, solve the equation for x.

x+2 4 − x−1 3 =2

Answer

x=−14

2.2-17 §2.2 source ↗

For the following exercises, solve each rational equation for x. State all x-values that are excluded from the solution set.

2− 3 x+4 = x+2 x+4

Answer

x≠−4; x=−3

2.2-19 §2.2 source ↗

For the following exercises, solve each rational equation for x. State all x-values that are excluded from the solution set.

3x x−1 + 2= 3 x−1

Answer

x≠1; when we solve this we get x=1, which is excluded, therefore NO solution

2.2-21 §2.2 source ↗

For the following exercises, solve each rational equation for x. State all x-values that are excluded from the solution set.

1 x = 1 5 + 3 2x

Answer

x≠0; x=− 5 2

2.2-23 §2.2 source ↗

For the following exercises, find the equation of the line using the point-slope formula. Write all the final equations using the slope-intercept form.

( 1,2 ) with a slope of − 4 5

Answer

y=− 4 5 x+ 14 5

2.2-25 §2.2 source ↗

For the following exercises, find the equation of the line using the point-slope formula. Write all the final equations using the slope-intercept form.

y-intercept is 2, and ( 4,−1 )

Answer

y=− 3 4 x+2

2.2-27 §2.2 source ↗

For the following exercises, find the equation of the line using the point-slope formula. Write all the final equations using the slope-intercept form.

( 1,3 ) and  ( 5,5 )

Answer

y= 1 2 x+ 5 2

2.2-29 §2.2 source ↗

For the following exercises, find the equation of the line using the point-slope formula. Write all the final equations using the slope-intercept form.

perpendicular to 3y=x−4 and passes through the point ( −2,1 ) .

Answer

y=−3x−5

2.2-31 §2.2 source ↗

For the following exercises, find the equation of the line using the given information.

( 1,7 ) and ( 3,7 )

Answer

y=7

2.2-33 §2.2 source ↗

For the following exercises, find the equation of the line using the given information.

The slope equals zero and it passes through the point ( 1,−4 ).

Answer

y=−4

2.2-35 §2.2 source ↗

For the following exercises, find the equation of the line using the given information.

(–1,3) and (4,–5)

Answer

8x+5y=7

2.2-37 §2.2 source ↗

For the following exercises, graph the pair of equations on the same axes, and state whether they are parallel, perpendicular, or neither.

3x−2y=5 6y−9x=6

Answer


Coordinate plane with the x and y axes ranging from negative 10 to 10. The functions 3 times x minus 2 times y = 5 and 6 times y minus 9 times x = 6 are graphed on the same plot. The lines do not cross.

Parallel

2.2-39 §2.2 source ↗

For the following exercises, graph the pair of equations on the same axes, and state whether they are parallel, perpendicular, or neither.

x=4 y=−3

Answer


Coordinate plane with the x and y axes ranging from negative 10 to 10. The function y = negative 3 and the line x = 4 are graphed on the same plot. These lines cross at a 90 degree angle.

Perpendicular

2.2-41 §2.2 source ↗

For the following exercises, find the slope of the line that passes through the given points.

( −3,2 ) and ( 4,−7 )

Answer

m=− 9 7

2.2-43 §2.2 source ↗

For the following exercises, find the slope of the line that passes through the given points.

( −1,−2 ) and ( 3,4 )

Answer

m= 3 2

2.2-45 §2.2 source ↗

For the following exercises, find the slope of the lines that pass through each pair of points and determine whether the lines are parallel or perpendicular.

( −1,3 ) and  ( 5,1 ) ( −2,3 ) and  ( 0,9 )

Answer

m 1 = − 1 3 , m 2 = 3; Perpendicular.

2.2-47 §2.2 source ↗

For the following exercises, express the equations in slope intercept form (rounding each number to the thousandths place). Enter this into a graphing calculator as Y1, then adjust the ymin and ymax values for your window to include where the y-intercept occurs. State your ymin and ymax values.

0.537x− 2.19y= 100

Answer

y= 0.245x− 45.662. Answers may vary. y min = −50, y max = −40

2.2-49 §2.2 source ↗

For the following exercises, express the equations in slope intercept form (rounding each number to the thousandths place). Enter this into a graphing calculator as Y1, then adjust the ymin and ymax values for your window to include where the y-intercept occurs. State your ymin and ymax values.

200−30y x =70

Answer

y= − 2.333x+ 6.667. Answers may vary. y min = −10,   y max = 10

2.2-51 §2.2 source ↗

For the following exercises, express the equations in slope intercept form (rounding each number to the thousandths place). Enter this into a graphing calculator as Y1, then adjust the ymin and ymax values for your window to include where the y-intercept occurs. State your ymin and ymax values.

Starting with the standard form of an equation Ax+By=C solve this expression for y in terms of A,B,C and x. Then put the expression in slope-intercept form.

Answer

y=− A B x+ C B

2.2-53 §2.2 source ↗

For the following exercises, express the equations in slope intercept form (rounding each number to the thousandths place). Enter this into a graphing calculator as Y1, then adjust the ymin and ymax values for your window to include where the y-intercept occurs. State your ymin and ymax values.

Given that the following coordinates are the vertices of a rectangle, prove that this truly is a rectangle by showing the slopes of the sides that meet are perpendicular.

(–1,1), (2,0), (3,3) and (0,4)

Answer

The slope for (−1,1)to (0,4)is 3. The slope for (−1,1)to (2,0)is  −1 3 . The slope for (2,0)to (3,3)is 3. The slope for (0,4)to (3,3)is  −1 3 .

Yes they are perpendicular.

2.2-55 §2.2 source ↗

For the following exercises, express the equations in slope intercept form (rounding each number to the thousandths place). Enter this into a graphing calculator as Y1, then adjust the ymin and ymax values for your window to include where the y-intercept occurs. State your ymin and ymax values.

The slope for a wheelchair ramp for a home has to be 1 12 . If the vertical distance from the ground to the door bottom is 2.5 ft, find the distance the ramp has to extend from the home in order to comply with the needed slope.

A right-angled triangle is shown with its horizontal leg labeled as x feet and its vertical leg labeled as 2.5 feet. The hypotenuse of the triangle is not labeled.

Answer

30 ft

2.2-57 §2.2 source ↗

For the following exercises, use this scenario: The cost of renting a car is $45/wk plus $0.25/mi traveled during that week. An equation to represent the cost would be y=45+.25x, where x is the number of miles traveled.

What is your cost if you travel 50 mi?

Answer

$57.50

2.2-59 §2.2 source ↗

For the following exercises, use this scenario: The cost of renting a car is $45/wk plus $0.25/mi traveled during that week. An equation to represent the cost would be y=45+.25x, where x is the number of miles traveled.

Suppose you have a maximum of $100 to spend for the car rental. What would be the maximum number of miles you could travel?

Answer

220 mi

Try It #1 §2.3 source ↗

Find a linear equation to solve for the following unknown quantities: One number is three more than twice another number. If the sum of the two numbers is 36, find the numbers.

Answer

11 and 25

Try It #2 §2.3 source ↗

Find a linear equation to model this real-world application: It costs ABC electronics company $2.50 per unit to produce a part used in a popular brand of desktop computers. The company has monthly operating expenses of $350 for utilities and $3,300 for salaries. What are the company’s monthly expenses?

Answer

C= 2.5x+ 3, 650

Try It #3 §2.3 source ↗

On Saturday morning, it took Jennifer 3.6 h to drive to her mother’s house for the weekend. On Sunday evening, due to heavy traffic, it took Jennifer 4 h to return home. Her speed was 5 mi/h slower on Sunday than on Saturday. What was her speed on Sunday?

Answer

45 mi/h

Try It #4 §2.3 source ↗

Find the dimensions of a rectangle given that the perimeter is 110 cm and the length is 1 cm more than twice the width.

Answer

L=37 cm, W=18 cm

Try It #5 §2.3 source ↗

A game room has a perimeter of 70 ft. The length is five more than twice the width. How many ft2 of new carpeting should be ordered?

Answer

250 ft2

2.3-1 §2.3 source ↗

To set up a model linear equation to fit real-world applications, what should always be the first step?

Answer

Answers may vary. Possible answers: We should define in words what our variable is representing. We should declare the variable. A heading.

2.3-3 §2.3 source ↗

If the total amount of money you had to invest was $2,000 and you deposit x amount in one investment, how can you represent the remaining amount?

Answer

2,000−x

2.3-5 §2.3 source ↗

If Bill was traveling v mi/h, how would you represent Daemon’s speed if he was traveling 10 mi/h faster?

Answer

v+10

2.3-7 §2.3 source ↗

For the following exercises, use the information to find a linear algebraic equation model to use to answer the question being asked.

Beth and Ann are joking that their combined ages equal Sam’s age. If Beth is twice Ann’s age and Sam is 69 yr old, what are Beth and Ann’s ages?

Answer

Ann: 23; Beth: 46

2.3-9 §2.3 source ↗

For the following exercises, use this scenario: Two different telephone carriers offer the following plans that a person is considering. Company A has a monthly fee of $20 and charges of $.05/min for calls. Company B has a monthly fee of $5 and charges $.10/min for calls.

Find the model of the total cost of Company A’s plan, using m for the minutes.

Answer

20+0.05m

2.3-11 §2.3 source ↗

For the following exercises, use this scenario: Two different telephone carriers offer the following plans that a person is considering. Company A has a monthly fee of $20 and charges of $.05/min for calls. Company B has a monthly fee of $5 and charges $.10/min for calls.

Find out how many minutes of calling would make the two plans equal.

Answer

300 min

2.3-13 §2.3 source ↗

For the following exercises, use this scenario: A wireless carrier offers the following plans that a person is considering. The Family Plan: $90 monthly fee, unlimited talk and text on up to 8 lines, and data charges of $40 for each device for up to 2 GB of data per device. The Mobile Share Plan: $120 monthly fee for up to 10 devices, unlimited talk and text for all the lines, and data charges of $35 for each device up to a shared total of 10 GB of data. Use P for the number of devices that need data plans as part of their cost.

Find the model of the total cost of the Family Plan.

Answer

90+40P

2.3-15 §2.3 source ↗

For the following exercises, use this scenario: A wireless carrier offers the following plans that a person is considering. The Family Plan: $90 monthly fee, unlimited talk and text on up to 8 lines, and data charges of $40 for each device for up to 2 GB of data per device. The Mobile Share Plan: $120 monthly fee for up to 10 devices, unlimited talk and text for all the lines, and data charges of $35 for each device up to a shared total of 10 GB of data. Use P for the number of devices that need data plans as part of their cost.

Assuming they stay under their data limit, find the number of devices that would make the two plans equal in cost.

Answer

6 devices

2.3-17 §2.3 source ↗

For exercises 17 and 18, use this scenario: A retired woman has $50,000 to invest but needs to make $6,000 a year from the interest to meet certain living expenses. One bond investment pays 15% annual interest. The rest of it she wants to put in a CD that pays 7%.

If we let x be the amount the woman invests in the 15% bond, how much will she be able to invest in the CD?

Answer

50,000−x

2.3-19 §2.3 source ↗

For exercises 17 and 18, use this scenario: A retired woman has $50,000 to invest but needs to make $6,000 a year from the interest to meet certain living expenses. One bond investment pays 15% annual interest. The rest of it she wants to put in a CD that pays 7%.

Two planes fly in opposite directions. One travels 450 mi/h and the other 550 mi/h. How long will it take before they are 4,000 mi apart?

Answer

4 h

2.3-21 §2.3 source ↗

For exercises 17 and 18, use this scenario: A retired woman has $50,000 to invest but needs to make $6,000 a year from the interest to meet certain living expenses. One bond investment pays 15% annual interest. The rest of it she wants to put in a CD that pays 7%.

Fiora starts riding her bike at 20 mi/h. After a while, she slows down to 12 mi/h, and maintains that speed for the rest of the trip. The whole trip of 70 mi takes her 4.5 h. For what distance did she travel at 20 mi/h?

Answer

She traveled for 2 h at 20 mi/h, or 40 miles.

2.3-23 §2.3 source ↗

For exercises 17 and 18, use this scenario: A retired woman has $50,000 to invest but needs to make $6,000 a year from the interest to meet certain living expenses. One bond investment pays 15% annual interest. The rest of it she wants to put in a CD that pays 7%.

Raúl has $20,000 to invest. His intent is to earn 11% interest on his investment. He can invest part of his money at 8% interest and part at 12% interest. How much does Raúl need to invest in each option to make get a total 11% return on his $20,000?

Answer

$5,000 at 8% and $15,000 at 12%

2.3-25 §2.3 source ↗

For the following exercises, use this scenario: A truck rental agency offers two kinds of plans. Plan A charges $75/wk plus $.10/mi driven. Plan B charges $100/wk plus $.05/mi driven.

Write the model equation for the cost of renting a truck with plan B.

Answer

B=100+.05x

2.3-27 §2.3 source ↗

For the following exercises, use this scenario: A truck rental agency offers two kinds of plans. Plan A charges $75/wk plus $.10/mi driven. Plan B charges $100/wk plus $.05/mi driven.

If Tim knows he has to travel 300 mi, which plan should he choose?

Answer

Plan A

2.3-29 §2.3 source ↗

For the following exercises, use the formula given to solve for the required value.

The formula F= m v 2 R relates force (F), velocity (v), mass , and resistance (m). Find R when m=45, v=7, and F=245.

Answer

R=9

2.3-31 §2.3 source ↗

For the following exercises, use the formula given to solve for the required value.

Sum= 1 1−r is the formula for an infinite series sum. If the sum is 5, find r.

Answer

r= 4 5 or 0.8

2.3-33 §2.3 source ↗

For the following exercises, solve for the given variable in the formula. After obtaining a new version of the formula, you will use it to solve a question.

Use the formula from the previous question to find the width, W, of a rectangle whose length is 15 and whose perimeter is 58.

Answer

W= P−2L 2 = 58−2(15) 2 = 14

2.3-35 §2.3 source ↗

For the following exercises, solve for the given variable in the formula. After obtaining a new version of the formula, you will use it to solve a question.

Use the formula from the previous question to find f when p= 8and q= 13.

Answer

f= pq p+q = 8(13) 8+13 = 104 21

2.3-37 §2.3 source ↗

For the following exercises, solve for the given variable in the formula. After obtaining a new version of the formula, you will use it to solve a question.

Use the formula from the previous question to find m when the coordinates of the point are ( 4,7 ) and b=12.

Answer

m= −5 4

2.3-39 §2.3 source ↗

For the following exercises, solve for the given variable in the formula. After obtaining a new version of the formula, you will use it to solve a question.

Solve for h: A= 1 2 h( b 1 + b 2 )

Answer

h= 2A b 1 + b 2

2.3-41 §2.3 source ↗

For the following exercises, solve for the given variable in the formula. After obtaining a new version of the formula, you will use it to solve a question.

Find the dimensions of an American football field. The length is 200 ft more than the width, and the perimeter is 1,040 ft. Find the length and width. Use the perimeter formula P=2L+2W.

Answer

length = 360 ft; width = 160 ft

2.3-43 §2.3 source ↗

For the following exercises, solve for the given variable in the formula. After obtaining a new version of the formula, you will use it to solve a question.

Using the formula in the previous exercise, find the distance that Susan travels if she is moving at a rate of 60 mi/h for 6.75 h.

Answer

405 mi

2.3-45 §2.3 source ↗

For the following exercises, solve for the given variable in the formula. After obtaining a new version of the formula, you will use it to solve a question.

If the area model for a triangle is A= 1 2 bh, find the area of a triangle with a height of 16 in. and a base of 11 in.

Answer

A=88in . 2

2.3-47 §2.3 source ↗

For the following exercises, solve for the given variable in the formula. After obtaining a new version of the formula, you will use it to solve a question.

Use the formula from the previous question to find the height to the nearest tenth of a triangle with a base of 15 and an area of 215.

Answer

28.7

2.3-49 §2.3 source ↗

For the following exercises, solve for the given variable in the formula. After obtaining a new version of the formula, you will use it to solve a question.

Solve for h: V=π r 2 h

Answer

h= V π r 2

2.3-51 §2.3 source ↗

For the following exercises, solve for the given variable in the formula. After obtaining a new version of the formula, you will use it to solve a question.

Solve for r: V=π r 2 h

Answer

r= V πh

2.3-53 §2.3 source ↗

For the following exercises, solve for the given variable in the formula. After obtaining a new version of the formula, you will use it to solve a question.

The formula for the circumference of a circle is C=2πr. Find the circumference of a circle with a diameter of 12 in. (diameter = 2r). Use the symbol π in your final answer.

Answer

C=12π

Try It #1 §2.4 source ↗

Express −24 in standard form.

Answer

−24 =0+2i 6

Try It #2 §2.4 source ↗

Plot the complex number −4−i on the complex plane.

Answer

Coordinate plane with the x and y axes ranging from negative 5 to 5. The point -4 i is plotted.

Try It #3 §2.4 source ↗

Subtract 2+5i from 3–4i.

Answer

(3−4i)− (2+5i)= 1−9i

Try It #4 §2.4 source ↗

Find the product: 1 2 ( 5−2i ).

Answer

5 2 −i

Try It #5 §2.4 source ↗

Multiply: ( 3−4i )( 2+3i ).

Answer

18+i

Try It #6 §2.4 source ↗

Find the complex conjugate of −3+4i.

Answer

−3−4i

Try It #7 §2.4 source ↗

Evaluate: i 18

Answer

−1

2.4-1 §2.4 source ↗

Explain how to add complex numbers.

Answer

Add the real parts together and the imaginary parts together.

2.4-3 §2.4 source ↗

Give an example to show that the product of two imaginary numbers is not always imaginary.

Answer

Possible answer: i times i equals -1, which is not imaginary.

2.4-5 §2.4 source ↗

For the following exercises, evaluate the algebraic expressions.

If y= x 2 +x−4, evaluate y given x=2i.

Answer

−8+2i

2.4-7 §2.4 source ↗

For the following exercises, evaluate the algebraic expressions.

If y= x 2 +3x+5, evaluate y given x=2+i.

Answer

14+7i

2.4-9 §2.4 source ↗

For the following exercises, evaluate the algebraic expressions.

If y= x+1 2−x , evaluate y given x=5i.

Answer

− 23 29 + 15 29 i

2.4-11 §2.4 source ↗

For the following exercises, plot the complex numbers on the complex plane.

1−2i

Answer


Coordinate plane with the x and y axes ranging from 5 to 5. The point 1 2i is plotted

2.4-13 §2.4 source ↗

For the following exercises, plot the complex numbers on the complex plane.

i

Answer


Coordinate plane with the x and y axes ranging from -5 to 5. The point i is plotted.

2.4-15 §2.4 source ↗

For the following exercises, perform the indicated operation and express the result as a simplified complex number.

(3+2i)+ (5−3i)

Answer

8−i

2.4-17 §2.4 source ↗

For the following exercises, perform the indicated operation and express the result as a simplified complex number.

(−5+3i)− (6−i)

Answer

−11+4i

2.4-19 §2.4 source ↗

For the following exercises, perform the indicated operation and express the result as a simplified complex number.

(−4+4i)− (−6+9i)

Answer

2−5i

2.4-21 §2.4 source ↗

For the following exercises, perform the indicated operation and express the result as a simplified complex number.

( 5−2i )(3i)

Answer

6+15i

2.4-23 §2.4 source ↗

For the following exercises, perform the indicated operation and express the result as a simplified complex number.

( −2+4i )( 8 )

Answer

−16+32i

2.4-25 §2.4 source ↗

For the following exercises, perform the indicated operation and express the result as a simplified complex number.

( −1+2i )(−2+3i)

Answer

−4−7i

2.4-27 §2.4 source ↗

For the following exercises, perform the indicated operation and express the result as a simplified complex number.

( 3+4i )( 3−4i )

Answer

25

2.4-29 §2.4 source ↗

For the following exercises, perform the indicated operation and express the result as a simplified complex number.

6−2i 3

Answer

2− 2 3 i

2.4-31 §2.4 source ↗

For the following exercises, perform the indicated operation and express the result as a simplified complex number.

6+4i i

Answer

4−6i

2.4-33 §2.4 source ↗

For the following exercises, perform the indicated operation and express the result as a simplified complex number.

3+4i 2−i

Answer

2 5 + 11 5 i

2.4-35 §2.4 source ↗

For the following exercises, perform the indicated operation and express the result as a simplified complex number.

−9 +3 −16

Answer

15i

2.4-37 §2.4 source ↗

For the following exercises, perform the indicated operation and express the result as a simplified complex number.

2+ −12 2

Answer

1+i 3

2.4-39 §2.4 source ↗

For the following exercises, perform the indicated operation and express the result as a simplified complex number.

i 8

Answer

1

2.4-41 §2.4 source ↗

For the following exercises, perform the indicated operation and express the result as a simplified complex number.

i 22

Answer

−1

2.4-43 §2.4 source ↗

For the following exercises, use a calculator to help answer the questions.

Evaluate (1−i) k for k=2,6, and 10. Predict the value if k=14.

Answer

128i

2.4-45 §2.4 source ↗

For the following exercises, use a calculator to help answer the questions.

Show that a solution of x 6 +1=0 is 3 2 + 1 2 i.

Answer

( 3 2 + 1 2 i ) 6 = −1

2.4-47 §2.4 source ↗

For the following exercises, evaluate the expressions, writing the result as a simplified complex number.

1 i + 4 i 3

Answer

3i

2.4-49 §2.4 source ↗

For the following exercises, evaluate the expressions, writing the result as a simplified complex number.

i 7 ( 1+ i 2 )

Answer

0

2.4-51 §2.4 source ↗

For the following exercises, evaluate the expressions, writing the result as a simplified complex number.

( 2+i )( 4−2i ) (1+i)

Answer

5−5i

2.4-53 §2.4 source ↗

For the following exercises, evaluate the expressions, writing the result as a simplified complex number.

( 3+i ) 2 ( 1+2i ) 2

Answer

−2i

2.4-55 §2.4 source ↗

For the following exercises, evaluate the expressions, writing the result as a simplified complex number.

4+i i + 3−4i 1−i

Answer

9 2 − 9 2 i

Try It #1 §2.5 source ↗

Factor and solve the quadratic equation: x 2 −5x−6=0.

Answer

(x−6)(x+1)= 0; x= 6, x= − 1

Try It #2 §2.5 source ↗

Solve the quadratic equation by factoring: x 2 −4x−21=0.

Answer

(x−7)(x+3)= 0, x=7, x=−3.

Try It #3 §2.5 source ↗

Solve by factoring: x 2 −25=0.

Answer

(x+5)(x−5)= 0, x=−5, x=5.

Try It #4 §2.5 source ↗

Solve using factoring by grouping: 12 x 2 + 11x+ 2= 0.

Answer

(3x+2)(4x+1)= 0, x=− 2 3 , x=− 1 4

Try It #5 §2.5 source ↗

Solve by factoring: x 3 + 11 x 2 + 10x= 0.

Answer

x= 0, x= −10, x= −1

Try It #6 §2.5 source ↗

Solve the quadratic equation using the square root property: 3 ( x−4 ) 2 =15.

Answer

x=4± 5

Try It #7 §2.5 source ↗

Solve by completing the square: x 2 −6x=13.

Answer

x=3± 22

Try It #8 §2.5 source ↗

Solve the quadratic equation using the quadratic formula: 9 x 2 +3x−2=0.

Answer

x=− 2 3 , x= 1 3

Try It #9 §2.5 source ↗

Use the Pythagorean Theorem to solve the right triangle problem: Leg a measures 4 units, leg b measures 3 units. Find the length of the hypotenuse.

Answer

5 units

2.5-1 §2.5 source ↗

How do we recognize when an equation is quadratic?

Answer

It is a second-degree equation (the highest variable exponent is 2).

2.5-3 §2.5 source ↗

When we solve a quadratic equation by factoring, why do we move all terms to one side, having zero on the other side?

Answer

We want to take advantage of the zero property of multiplication in the fact that if a⋅b=0 then it must follow that each factor separately offers a solution to the product being zero: a=0orb=0.

2.5-5 §2.5 source ↗

Describe two scenarios where using the square root property to solve a quadratic equation would be the most efficient method.

Answer

One, when no linear term is present (no x term), such as x 2 =16. Two, when the equation is already in the form (ax+b) 2 =d.

2.5-7 §2.5 source ↗

For the following exercises, solve the quadratic equation by factoring.

x 2 −9x+18=0

Answer

x=6, x=3

2.5-9 §2.5 source ↗

For the following exercises, solve the quadratic equation by factoring.

6 x 2 +17x+5=0

Answer

x= −5 2 , x= −1 3

2.5-11 §2.5 source ↗

For the following exercises, solve the quadratic equation by factoring.

3 x 2 −75=0

Answer

x=5, x=−5

2.5-13 §2.5 source ↗

For the following exercises, solve the quadratic equation by factoring.

4 x 2 =9

Answer

x= −3 2 , x= 3 2

2.5-15 §2.5 source ↗

For the following exercises, solve the quadratic equation by factoring.

5 x 2 =5x+30

Answer

x=−2,3

2.5-17 §2.5 source ↗

For the following exercises, solve the quadratic equation by factoring.

7 x 2 +3x=0

Answer

x=0, x= −3 7

2.5-19 §2.5 source ↗

For the following exercises, solve the quadratic equation by using the square root property.

x 2 =36

Answer

x=−6, x=6

2.5-21 §2.5 source ↗

For the following exercises, solve the quadratic equation by using the square root property.

( x−1 ) 2 =25

Answer

x=6, x=−4

2.5-23 §2.5 source ↗

For the following exercises, solve the quadratic equation by using the square root property.

( 2x+1 ) 2 =9

Answer

x=1, x=−2

2.5-25 §2.5 source ↗

For the following exercises, solve the quadratic equation by completing the square. Show each step.

x 2 −9x−22=0

Answer

x=−2, x=11

2.5-27 §2.5 source ↗

For the following exercises, solve the quadratic equation by completing the square. Show each step.

x 2 −6x=13

Answer

x=3± 22

2.5-29 §2.5 source ↗

For the following exercises, solve the quadratic equation by completing the square. Show each step.

2+z=6 z 2

Answer

z= 2 3 , z=− 1 2

2.5-31 §2.5 source ↗

For the following exercises, solve the quadratic equation by completing the square. Show each step.

2 x 2 −3x−1=0

Answer

x= 3± 17 4

2.5-33 §2.5 source ↗

For the following exercises, determine the discriminant, and then state how many solutions there are and the nature of the solutions. Do not solve.

x 2 +4x+7=0

Answer

Not real

2.5-35 §2.5 source ↗

For the following exercises, determine the discriminant, and then state how many solutions there are and the nature of the solutions. Do not solve.

9 x 2 − 30x+ 25= 0

Answer

One rational

2.5-37 §2.5 source ↗

For the following exercises, determine the discriminant, and then state how many solutions there are and the nature of the solutions. Do not solve.

6 x 2 −x−2=0

Answer

Two real; rational

2.5-39 §2.5 source ↗

For the following exercises, solve the quadratic equation by using the quadratic formula. If the solutions are not real, state No Real Solution.

x 2 +x=4

Answer

x= −1± 17 2

2.5-41 §2.5 source ↗

For the following exercises, solve the quadratic equation by using the quadratic formula. If the solutions are not real, state No Real Solution.

3 x 2 −5x+1=0

Answer

x= 5± 13 6

2.5-43 §2.5 source ↗

For the following exercises, solve the quadratic equation by using the quadratic formula. If the solutions are not real, state No Real Solution.

4+ 1 x − 1 x 2 =0

Answer

x= −1± 17 8

2.5-45 §2.5 source ↗

For the following exercises, enter the expressions into your graphing utility and find the zeroes to the equation (the x-intercepts) by using 2nd CALC 2:zero. Recall finding zeroes will ask left bound (move your cursor to the left of the zero,enter), then right bound (move your cursor to the right of the zero,enter), then guess (move your cursor between the bounds near the zero, enter). Round your answers to the nearest thousandth.

Y 1 = −3 x 2 + 8x− 1

Answer

x≈0.131 and x≈2.535

2.5-47 §2.5 source ↗

For the following exercises, enter the expressions into your graphing utility and find the zeroes to the equation (the x-intercepts) by using 2nd CALC 2:zero. Recall finding zeroes will ask left bound (move your cursor to the left of the zero,enter), then right bound (move your cursor to the right of the zero,enter), then guess (move your cursor between the bounds near the zero, enter). Round your answers to the nearest thousandth.

To solve the quadratic equation x 2 +5x−7=4, we can graph these two equations

Y 1 = x 2 +5x−7 Y 2 =4

and find the points of intersection. Recall 2nd CALC 5:intersection. Do this and find the solutions to the nearest tenth.

Answer

x≈−6.7 and x≈1.7

2.5-49 §2.5 source ↗

For the following exercises, enter the expressions into your graphing utility and find the zeroes to the equation (the x-intercepts) by using 2nd CALC 2:zero. Recall finding zeroes will ask left bound (move your cursor to the left of the zero,enter), then right bound (move your cursor to the right of the zero,enter), then guess (move your cursor between the bounds near the zero, enter). Round your answers to the nearest thousandth.

Beginning with the general form of a quadratic equation, a x 2 +bx+c=0, solve for x by using the completing the square method, thus deriving the quadratic formula.

Answer

a x 2 +bx+c = 0 x 2 + b a x = −c a x 2 + b a x+ b 2 4 a 2 = −c a + b 4 a 2 ( x+ b 2a ) 2 = b 2 −4ac 4 a 2 x+ b 2a = ± b 2 −4ac 4 a 2 x = −b± b 2 −4ac 2a

2.5-51 §2.5 source ↗

For the following exercises, enter the expressions into your graphing utility and find the zeroes to the equation (the x-intercepts) by using 2nd CALC 2:zero. Recall finding zeroes will ask left bound (move your cursor to the left of the zero,enter), then right bound (move your cursor to the right of the zero,enter), then guess (move your cursor between the bounds near the zero, enter). Round your answers to the nearest thousandth.

A person has a garden that has a length 10 feet longer than the width. Set up a quadratic equation to find the dimensions of the garden if its area is 119 ft.2. Solve the quadratic equation to find the length and width.

Answer

x(x+10)= 119; 7 ft. and 17 ft.

2.5-53 §2.5 source ↗

For the following exercises, enter the expressions into your graphing utility and find the zeroes to the equation (the x-intercepts) by using 2nd CALC 2:zero. Recall finding zeroes will ask left bound (move your cursor to the left of the zero,enter), then right bound (move your cursor to the right of the zero,enter), then guess (move your cursor between the bounds near the zero, enter). Round your answers to the nearest thousandth.

Suppose that an equation is given p= −2 x 2 + 280x− 1000, where x represents the number of items sold at an auction and p is the profit made by the business that ran the auction. How many items sold would make this profit a maximum? Solve this by graphing the expression in your graphing utility and finding the maximum using 2nd CALC maximum. To obtain a good window for the curve, set x [0,200] and y [0,10000].

Answer

maximum at x=70

2.5-55 §2.5 source ↗

For the following exercises, enter the expressions into your graphing utility and find the zeroes to the equation (the x-intercepts) by using 2nd CALC 2:zero. Recall finding zeroes will ask left bound (move your cursor to the left of the zero,enter), then right bound (move your cursor to the right of the zero,enter), then guess (move your cursor between the bounds near the zero, enter). Round your answers to the nearest thousandth.

The cost function for a certain company is C=60x+300 and the revenue is given by R= 100x− 0.5 x 2 . Recall that profit is revenue minus cost. Set up a quadratic equation and find two values of x (production level) that will create a profit of $300.

Answer

The quadratic equation would be (100x−0.5 x 2 )− (60x+300)= 300. The two values of x are 20 and 60.

2.5-57 §2.5 source ↗

For the following exercises, enter the expressions into your graphing utility and find the zeroes to the equation (the x-intercepts) by using 2nd CALC 2:zero. Recall finding zeroes will ask left bound (move your cursor to the left of the zero,enter), then right bound (move your cursor to the right of the zero,enter), then guess (move your cursor between the bounds near the zero, enter). Round your answers to the nearest thousandth.

A vacant lot is being converted into a community garden. The garden and the walkway around its perimeter have an area of 378 ft2. Find the width of the walkway if the garden is 12 ft. wide by 15 ft. long.

A rectangle inside of a larger rectangle. The smaller rectangle has the length labeled: 15 feet and the width labeled: 12 feet. The distance between the two rectangles is labeled as x on all four sides.

Answer

3 feet

Try It #1 §2.6 source ↗

Evaluate 64 − 1 3 .

Answer

1 4

Try It #2 §2.6 source ↗

Solve the equation x 3 2 =125.

Answer

25

Try It #3 §2.6 source ↗

Solve: ( x+5 ) 3 2 =8.

Answer

{ −1 }

Try It #4 §2.6 source ↗

Solve by factoring: 12 x 4 =3 x 2 .

Answer

0, 1 2 , − 1 2

Try It #5 §2.6 source ↗

Solve the radical equation: x+3 =3x−1

Answer

1; extraneous solution − 2 9

Try It #6 §2.6 source ↗

Solve the equation with two radicals: 3x+7 + x+2 =1.

Answer

−2; extraneous solution −1

Try It #7 §2.6 source ↗

Solve the absolute value equation: |1− 4x|+ 8= 13.

Answer

−1, 3 2

Try It #8 §2.6 source ↗

Solve using substitution: x 4 −8 x 2 −9=0.

Answer

−3,3,−i,i

Try It #9 §2.6 source ↗

Solve: ( x−5 ) 2 − 4(x−5)− 21= 0.

Answer

2,12

Try It #10 §2.6 source ↗

Solve 3x+2 x−2 + 1 x = −2 x 2 −2x .

Answer

−1 (0 is not a solution).

2.6-1 §2.6 source ↗

In a radical equation, what does it mean if a number is an extraneous solution?

Answer

This is not a solution to the radical equation, it is a value obtained from squaring both sides and thus changing the signs of an equation which has caused it not to be a solution in the original equation.

2.6-3 §2.6 source ↗

Your friend tries to calculate the value − 9 3 2 and keeps getting an ERROR message. What mistake are they probably making?

Answer

They are probably trying to enter negative 9, but taking the square root of −9 is not a real number. The negative sign is in front of this, so your friend should be taking the square root of 9, cubing it, and then putting the negative sign in front, resulting in −27.

2.6-5 §2.6 source ↗

Explain how to change a rational exponent into the correct radical expression.

Answer

A rational exponent is a fraction: the denominator of the fraction is the root or index number and the numerator is the power to which it is raised.

2.6-7 §2.6 source ↗

For the following exercises, solve the rational exponent equation. Use factoring where necessary.

x 3 4 =27

Answer

x=81

2.6-9 §2.6 source ↗

For the following exercises, solve the rational exponent equation. Use factoring where necessary.

( x−1 ) 3 4 =8

Answer

x=17

2.6-11 §2.6 source ↗

For the following exercises, solve the rational exponent equation. Use factoring where necessary.

x 2 3 − 5 x 1 3 + 6= 0

Answer

x= 8,   x= 27

2.6-13 §2.6 source ↗

For the following exercises, solve the following polynomial equations by grouping and factoring.

x 3 + 2 x 2 − x− 2= 0

Answer

x=−2,1,−1

2.6-15 §2.6 source ↗

For the following exercises, solve the following polynomial equations by grouping and factoring.

4 y 3 −9y=0

Answer

y= 0,    3 2 ,    −3 2

2.6-17 §2.6 source ↗

For the following exercises, solve the following polynomial equations by grouping and factoring.

m 3 + m 2 −m−1=0

Answer

m=1,−1

2.6-19 §2.6 source ↗

For the following exercises, solve the following polynomial equations by grouping and factoring.

5 x 3 + 45x= 2 x 2 + 18

Answer

x= 2 5 , ±3 i

2.6-21 §2.6 source ↗

For the following exercises, solve the radical equation. Be sure to check all solutions to eliminate extraneous solutions.

x−7 =5

Answer

x=32

2.6-23 §2.6 source ↗

For the following exercises, solve the radical equation. Be sure to check all solutions to eliminate extraneous solutions.

3t+5 =7

Answer

t= 44 3

2.6-25 §2.6 source ↗

For the following exercises, solve the radical equation. Be sure to check all solutions to eliminate extraneous solutions.

12−x =x

Answer

x=3

2.6-27 §2.6 source ↗

For the following exercises, solve the radical equation. Be sure to check all solutions to eliminate extraneous solutions.

3x+7 + x+2 =1

Answer

x=−2

2.6-29 §2.6 source ↗

For the following exercises, solve the equation involving absolute value.

| 3x−4 |=8

Answer

x=4, −4 3

2.6-31 §2.6 source ↗

For the following exercises, solve the equation involving absolute value.

| 1−4x |−1=5

Answer

x= −5 4 , 7 4

2.6-33 §2.6 source ↗

For the following exercises, solve the equation involving absolute value.

| 2x−1 |−7=−2

Answer

x=3,−2

2.6-35 §2.6 source ↗

For the following exercises, solve the equation involving absolute value.

| x+5 |=0

Answer

x=−5

2.6-37 §2.6 source ↗

For the following exercises, solve the equation by identifying the quadratic form. Use a substitute variable and find all real solutions by factoring.

x 4 −10 x 2 +9=0

Answer

x=1,−1,3,-3

2.6-39 §2.6 source ↗

For the following exercises, solve the equation by identifying the quadratic form. Use a substitute variable and find all real solutions by factoring.

( x 2 −1 ) 2 + ( x 2 −1)− 12= 0

Answer

x=2,−2

2.6-41 §2.6 source ↗

For the following exercises, solve the equation by identifying the quadratic form. Use a substitute variable and find all real solutions by factoring.

( x−3 ) 2 −4=0

Answer

x=1,5

2.6-43 §2.6 source ↗

For the following exercises, solve for the unknown variable.

| x | 2 =x

Answer

x ≥ 0

2.6-45 §2.6 source ↗

For the following exercises, solve for the unknown variable.

| x 2 + 2x− 36|= 12

Answer

x=4,6,−6,−8

2.6-47 §2.6 source ↗

For the following exercises, use the model for the period of a pendulum, T, such that T=2π L g , where the length of the pendulum is L and the acceleration due to gravity is g.

If the gravity is 32 ft/s2 and the period equals 1 s, find the length to the nearest in. (12 in. = 1 ft). Round your answer to the nearest in.

Answer

10 in.

2.6-49 §2.6 source ↗

For the following exercises, use a model for body surface area, BSA, such that BSA= wh 3600 , where w = weight in kg and h = height in cm.

Find the weight of a 177-cm male to the nearest kg whose BSA=2.1.

Answer

90 kg

Try It #1 §2.7 source ↗

Use interval notation to indicate all real numbers between and including −3 and 5.

Answer

[ −3,5 ]

Try It #2 §2.7 source ↗

Express all real numbers less than −2 or greater than or equal to 3 in interval notation.

Answer

( −∞,−2 )∪[ 3,∞ )

Try It #3 §2.7 source ↗

Solve: 3x−2<1.

Answer

x<1

Try It #4 §2.7 source ↗

Solve: 4x+7≥2x−3.

Answer

x≥−5

Try It #5 §2.7 source ↗

Solve the inequality and write the answer using interval notation: − x+ 4< 1 2 x+ 1.

Answer

( 2,∞ )

Try It #6 §2.7 source ↗

Solve the inequality and write the answer in interval notation: − 5 6 x≤ 3 4 + 8 3 x.

Answer

[ − 3 14 ,∞ )

Try It #7 §2.7 source ↗

Solve the compound inequality: 4< 2x− 8≤10.

Answer

6< x≤9​or(6,9]

Try It #8 §2.7 source ↗

Solve the compound inequality: 3y< 4− 5y< 5+ 3y.

Answer

( − 1 8 , 1 2 )

Try It #9 §2.7 source ↗

Describe all x-values within a distance of 3 from the number 2.

Answer

| x−2 |≤3

Try It #10 §2.7 source ↗

Solve −2| k−4 |≤−6.

Answer

k≤1 or k≥7; in interval notation, this would be (−∞,1]∪[7,∞).

A coordinate plane with the x-axis ranging from -1 to 9 and the y-axis ranging from -3 to 8. The function y = -2|k 4| + 6 is graphed and everything above the function is shaded in.A coordinate plane with the x-axis ranging from -1 to 9 and the y-axis ranging from -3 to 8. The function y = -2|k 4| + 6 is graphed and everything above the function is shaded in.

2.7-1 §2.7 source ↗

When solving an inequality, explain what happened from Step 1 to Step 2:

Step 1 −2x>6 Step 2 x<−3

Answer

When we divide both sides by a negative it changes the sign of both sides so the sense of the inequality sign changes.

2.7-3 §2.7 source ↗

When writing our solution in interval notation, how do we represent all the real numbers?

Answer

( −∞,∞ )

2.7-5 §2.7 source ↗

Describe how to graph y=| x−3 |

Answer

We start by finding the x-intercept, or where the function = 0. Once we have that point, which is (3,0), we graph to the right the straight line graph y=x−3, and then when we draw it to the left we plot positive y values, taking the absolute value of them.

2.7-7 §2.7 source ↗

For the following exercises, solve the inequality. Write your final answer in interval notation.

3x+2≥7x−1

Answer

( −∞, 3 4 ]

2.7-9 §2.7 source ↗

For the following exercises, solve the inequality. Write your final answer in interval notation.

4(x+3)≥2x−1

Answer

[ − 13 2 ,∞ )

2.7-11 §2.7 source ↗

For the following exercises, solve the inequality. Write your final answer in interval notation.

−5(x−1)+ 3> 3x− 4− 4x

Answer

( −∞,3 )

2.7-13 §2.7 source ↗

For the following exercises, solve the inequality. Write your final answer in interval notation.

x+3 8 − x+5 5 ≥ 3 10

Answer

( −∞,− 37 3 ]

2.7-15 §2.7 source ↗

For the following exercises, solve the inequality involving absolute value. Write your final answer in interval notation.

| x+9 |≥−6

Answer

All real numbers ( −∞,∞ )

2.7-17 §2.7 source ↗

For the following exercises, solve the inequality involving absolute value. Write your final answer in interval notation.

|3x− 1|> 11

Answer

( −∞,− 10 3 )∪( 4,∞ )

2.7-19 §2.7 source ↗

For the following exercises, solve the inequality involving absolute value. Write your final answer in interval notation.

| x−2 |+4≥10

Answer

( −∞,−4 ]∪[ 8,+∞ )

2.7-21 §2.7 source ↗

For the following exercises, solve the inequality involving absolute value. Write your final answer in interval notation.

|x−7|<−4

Answer

No solution

2.7-23 §2.7 source ↗

For the following exercises, solve the inequality involving absolute value. Write your final answer in interval notation.

| x−3 4 |<2

Answer

( −5,11 )

2.7-25 §2.7 source ↗

For the following exercises, describe all the x-values within or including a distance of the given values.

Distance of 3 units from the number 9

Answer

[ 6,12 ]

2.7-27 §2.7 source ↗

For the following exercises, describe all the x-values within or including a distance of the given values.

Distance of 11 units from the number 1

Answer

[ −10,12 ]

2.7-29 §2.7 source ↗

For the following exercises, solve the compound inequality. Express your answer using inequality signs, and then write your answer using interval notation.

3x+ 1> 2x− 5> x− 7

Answer

x>−6andx>−2 Take the intersection of two sets. x>−2, (−2,+∞)

2.7-31 §2.7 source ↗

For the following exercises, solve the compound inequality. Express your answer using inequality signs, and then write your answer using interval notation.

2x− 5< −11or 5x+ 1≥6

Answer

x<−3 or x≥1 Take the union of the two sets. (−∞,−3) ∪ ​ ​ [1,∞)

2.7-33 §2.7 source ↗

For the following exercises, graph the function. Observe the points of intersection and shade the x-axis representing the solution set to the inequality. Show your graph and write your final answer in interval notation.

|x−1|>2

Answer

( −∞,−1 )∪( 3,∞ )


A coordinate plane where the x and y axes both range from -10 to 10. The function |x 1| is graphed and labeled along with the line y = 2. Along the x-axis there is an open circle at the point -1 with an arrow extending leftward from it. Also along the x-axis is an open circle at the point 3 with an arrow extending rightward from it.

2.7-35 §2.7 source ↗

For the following exercises, graph the function. Observe the points of intersection and shade the x-axis representing the solution set to the inequality. Show your graph and write your final answer in interval notation.

| x+7 |≤4

Answer

[ −11,−3 ]


A coordinate plane with the x-axis ranging from -14 to 10 and the y-axis ranging from -1 to 10. The function y = |x + 7| and the line y = 4 are graphed. On the x-axis theres a dot on the points -11 and -3 with a line connecting them.

2.7-37 §2.7 source ↗

For the following exercises, graph the function. Observe the points of intersection and shade the x-axis representing the solution set to the inequality. Show your graph and write your final answer in interval notation.

| x−2 |<0

Answer

It is never less than zero. No solution.


A coordinate plane with the x and y axes ranging from -10 to 10. The function y = |x -2| and the line y = 0 are graphed.

2.7-39 §2.7 source ↗

For the following exercises, graph both straight lines (left-hand side being y1 and right-hand side being y2) on the same axes. Find the point of intersection and solve the inequality by observing where it is true comparing the y-values of the lines.

x−2>2x+1

Answer

Where the blue line is above the orange line; point of intersection is x=−3.

( −∞,−3 )


A coordinate plane with the x and y axes ranging from -10 to 10. The lines y = x - 2 and y = 2x + 1 are graphed on the same axes.

2.7-41 §2.7 source ↗

For the following exercises, graph both straight lines (left-hand side being y1 and right-hand side being y2) on the same axes. Find the point of intersection and solve the inequality by observing where it is true comparing the y-values of the lines.

1 2 x+ 1> 1 2 x− 5

Answer

Where the blue line is above the orange line; always. All real numbers.

(−∞,−∞)


A coordinate plane with the x and y axes ranging from -10 to 10. The lines y = x/2 +1 and y = x/2 5 are both graphed on the same axes.

2.7-43 §2.7 source ↗

For the following exercises, write the set in interval notation.

{ x| −1<x<3 }

Answer

( −1,3 )

2.7-45 §2.7 source ↗

For the following exercises, write the set in interval notation.

{ x| x<4 }

Answer

( −∞,4 )

2.7-47 §2.7 source ↗

For the following exercises, write the interval in set-builder notation.

( −∞,6 )

Answer

{ x| x<6 }

2.7-49 §2.7 source ↗

For the following exercises, write the interval in set-builder notation.

[−3,5)

Answer

{ x| −3≤x<5 }

2.7-51 §2.7 source ↗

For the following exercises, write the set of numbers represented on the number line in interval notation.

A number line with two tick marks labeled: -2 and 1 respectively. There is an open circle around the -2 and a dot on the 1 with an arrow connecting the two.

Answer

( −2,1 ]

2.7-53 §2.7 source ↗

For the following exercises, write the set of numbers represented on the number line in interval notation.

Number line with one tick mark labeled 4. There is a dot on the tick mark and an arrow extending leftward from the dot.

Answer

( −∞,4 ]

2.7-55 §2.7 source ↗

For the following exercises, input the left-hand side of the inequality as a Y1 graph in your graphing utility. Enter y2 = the right-hand side. Entering the absolute value of an expression is found in the MATH menu, Num, 1:abs(. Find the points of intersection, recall (2nd CALC 5:intersection, 1st curve, enter, 2nd curve, enter, guess, enter). Copy a sketch of the graph and shade the x-axis for your solution set to the inequality. Write final answers in interval notation.

−1 2 |x+ 2|< 4

Answer

Where the blue is below the orange; always. All real numbers. (−∞,+∞).


A coordinate plane with the x and y axes ranging from -10 to 10. The function y = -0.5|x + 2| and the line y = 4 are graphed on the same axes. A line runs along the entire x-axis.

2.7-57 §2.7 source ↗

For the following exercises, input the left-hand side of the inequality as a Y1 graph in your graphing utility. Enter y2 = the right-hand side. Entering the absolute value of an expression is found in the MATH menu, Num, 1:abs(. Find the points of intersection, recall (2nd CALC 5:intersection, 1st curve, enter, 2nd curve, enter, guess, enter). Copy a sketch of the graph and shade the x-axis for your solution set to the inequality. Write final answers in interval notation.

| x−4 |<3

Answer

Where the blue is below the orange; ( 1,7 ).


A coordinate plane with the x and y axes ranging from -10 to 10. The function y = |x 4| and the line y = 3 are graphed on the same axes. Along the x-axis the points 1 and 7 have an open circle around them and a line connects the two.

2.7-59 §2.7 source ↗

For the following exercises, input the left-hand side of the inequality as a Y1 graph in your graphing utility. Enter y2 = the right-hand side. Entering the absolute value of an expression is found in the MATH menu, Num, 1:abs(. Find the points of intersection, recall (2nd CALC 5:intersection, 1st curve, enter, 2nd curve, enter, guess, enter). Copy a sketch of the graph and shade the x-axis for your solution set to the inequality. Write final answers in interval notation.

Solve |3x+ 1|= |2x+ 3|

Answer

x=2, −4 5

2.7-61 §2.7 source ↗

For the following exercises, input the left-hand side of the inequality as a Y1 graph in your graphing utility. Enter y2 = the right-hand side. Entering the absolute value of an expression is found in the MATH menu, Num, 1:abs(. Find the points of intersection, recall (2nd CALC 5:intersection, 1st curve, enter, 2nd curve, enter, guess, enter). Copy a sketch of the graph and shade the x-axis for your solution set to the inequality. Write final answers in interval notation.

x−5 x+7 ≤0, x≠−7

Answer

( −7,5 ]

2.7-63 §2.7 source ↗

For the following exercises, input the left-hand side of the inequality as a Y1 graph in your graphing utility. Enter y2 = the right-hand side. Entering the absolute value of an expression is found in the MATH menu, Num, 1:abs(. Find the points of intersection, recall (2nd CALC 5:intersection, 1st curve, enter, 2nd curve, enter, guess, enter). Copy a sketch of the graph and shade the x-axis for your solution set to the inequality. Write final answers in interval notation.

In chemistry the volume for a certain gas is given by V=20T, where V is measured in cc and T is temperature in ºC. If the temperature varies between 80ºC and 120ºC, find the set of volume values.

Answer

80≤T≤120 1,600≤20T≤2,400

[ 1,600, 2,400 ]

2.R-1 §2.R source ↗

For the following exercises, find the x-intercept and the y-intercept without graphing.

4x−3y=12

Answer

x-intercept: ( 3,0 ); y-intercept: ( 0,−4 )

2.R-3 §2.R source ↗

For the following exercises, solve for y in terms of x, putting the equation in slope–intercept form.

5x=3y−12

Answer

y= 5 3 x+4

2.R-5 §2.R source ↗

For the following exercises, find the distance between the two points.

( −2,5 )( 4,−1 )

Answer

72 =6 2

2.R-7 §2.R source ↗

For the following exercises, find the distance between the two points.

Find the distance between the two points (−71,432) and (511,218) using your calculator, and round your answer to the nearest thousandth.

Answer

620.097

2.R-9 §2.R source ↗

For the following exercises, find the coordinates of the midpoint of the line segment that joins the two given points.

( −13,5 ) and ( 17,18 )

Answer

midpoint is ( 2, 23 2 )

2.R-11 §2.R source ↗

For the following exercises, construct a table and graph the equation by plotting at least three points.

4x−3y=6

Answer

x y
0 −2
3 2
6 6


A coordinate plane with the x and y axes ranging from -10 to 10. The points (0,-2); (3,2) and (6,6) are plotted and a line runs through all these points.

2.R-13 §2.R source ↗

For the following exercises, solve for x.

3(x+2)− 10= x+ 4

Answer

x=4

2.R-15 §2.R source ↗

For the following exercises, solve for x.

12− 5(x+1)= 2x− 5

Answer

x= 12 7

2.R-17 §2.R source ↗

For the following exercises, solve for x. State all x-values that are excluded from the solution set.

x x 2 −9 + 4 x+3 = 3 x 2 −9 x≠3,−3

Answer

No solution

2.R-19 §2.R source ↗

For the following exercises, find the equation of the line using the point-slope formula.

Passes through these two points: ( −2,1 ),( 4,2 ).

Answer

y= 1 6 x+ 4 3

2.R-21 §2.R source ↗

For the following exercises, find the equation of the line using the point-slope formula.

Passes through the point ( −3,4 ) and is parallel to the graph y= 2 3 x+5.

Answer

y= 2 3 x+6

2.R-23 §2.R source ↗

For the following exercises, write and solve an equation to answer each question.

The number of male fish in the tank is five more than three times the number of females. If the total number of fish is 73, how many of each sex are in the tank?

Answer

females 17, males 56

2.R-25 §2.R source ↗

For the following exercises, write and solve an equation to answer each question.

A truck rental is $25 plus $.30/mi. Find out how many miles Ken traveled if his bill was $50.20.

Answer

84 mi

2.R-27 §2.R source ↗

For the following exercises, use the quadratic equation to solve.

2 x 2 +3x+7=0

Answer

x=− 3 4 ± i 47 4

2.R-29 §2.R source ↗

For the following exercises, name the horizontal component and the vertical component.

−2−i

Answer

horizontal component −2; vertical component −1

2.R-31 §2.R source ↗

For the following exercises, perform the operations indicated.

(2+3i)− (−5−8i)

Answer

7+11i

2.R-33 §2.R source ↗

For the following exercises, perform the operations indicated.

−16 +4 −9

Answer

16i

2.R-35 §2.R source ↗

For the following exercises, perform the operations indicated.

(3−5i) 2

Answer

−16−30i

2.R-37 §2.R source ↗

For the following exercises, perform the operations indicated.

−2 ( −8 − 5 )

Answer

−4−i 10

2.R-39 §2.R source ↗

For the following exercises, perform the operations indicated.

3+7i i

Answer

x=7−3i

2.R-41 §2.R source ↗

For the following exercises, solve the quadratic equation by factoring.

3 x 2 + 18x+ 15= 0

Answer

x=−1,−5

2.R-43 §2.R source ↗

For the following exercises, solve the quadratic equation by factoring.

7 x 2 −9x=0

Answer

x=0, 9 7

2.R-45 §2.R source ↗

For the following exercises, solve the quadratic equation by using the square-root property.

( x−4 ) 2 =36

Answer

x=10,−2

2.R-47 §2.R source ↗

For the following exercises, solve the quadratic equation by completing the square.

4 x 2 +2x−1=0

Answer

x= −1± 5 4

2.R-49 §2.R source ↗

For the following exercises, solve the quadratic equation by using the quadratic formula. If the solutions are not real, state No real solution.

15 x 2 −x−2=0

Answer

x= 2 5 , −1 3

2.R-51 §2.R source ↗

For the following exercises, solve the quadratic equation by the method of your choice.

x 2 =10x+3

Answer

x=5±2 7

2.R-53 §2.R source ↗

For the following exercises, solve the equations.

x 1 2 −4 x 1 4 =0

Answer

x=0,256

2.R-55 §2.R source ↗

For the following exercises, solve the equations.

3 x 5 −6 x 3 =0

Answer

x=0,± 2

2.R-57 §2.R source ↗

For the following exercises, solve the equations.

3x+7 + x+2 =1

Answer

x=−2

2.R-59 §2.R source ↗

For the following exercises, solve the equations.

| 2x+3 |−5=9

Answer

x= 11 2 , −17 2

2.R-61 §2.R source ↗

For the following exercises, solve the inequality. Write your final answer in interval notation.

− 2x+ 5> x− 7

Answer

( −∞,4 )

2.R-63 §2.R source ↗

For the following exercises, solve the inequality. Write your final answer in interval notation.

| 3x+2 |+1≤9

Answer

[ −10 3 ,2 ]

2.R-65 §2.R source ↗

For the following exercises, solve the inequality. Write your final answer in interval notation.

| x−3 |<−4

Answer

No solution

2.R-67 §2.R source ↗

For the following exercises, solve the compound inequality. Write your answer in interval notation.

3y< 1− 2y< 5+ y

Answer

( − 4 3 , 1 5 )

2.R-69 §2.R source ↗

For the following exercises, graph as described.

Graph both straight lines (left-hand side being y1 and right-hand side being y2) on the same axes. Find the point of intersection and solve the inequality by observing where it is true comparing the y-values of the lines. See the interval where the inequality is true.

x+3<3x−4

Answer

Where the blue is below the orange line; point of intersection is x=3.5.

( 3.5,∞ )


A coordinate plane with the x and y axes ranging from -10 to 10. The lines y = x + 3 and y = 3x -4 graphed on the same axes.

2.T-1 §2.T source ↗

Graph the following: 2y=3x+4.

Answer

y= 3 2 x+2

x y
0 2
2 5
4 8


A coordinate plane with the x and y axes ranging from -10 to 10. The line going through the points (0,2); (2,5); and (4,8) is graphed.

2.T-3 §2.T source ↗

Find the x- and y-intercepts of this equation, and sketch the graph of the line using just the intercepts plotted.

3x−4y=12

Answer

( 0,−3 ) ( 4,0 )


A coordinate plane with the x and y axes ranging from -10 to 10. The points (4,0) and (0,-3) are plotted with a line running through them.

2.T-5 §2.T source ↗

Write the interval notation for the set of numbers represented by { x| x≤9 }.

Answer

( −∞,9 ]

2.T-7 §2.T source ↗

Solve for x: 3(2x−5)− 3(x−7)= 2x− 9.

Answer

x=−15

2.T-9 §2.T source ↗

Solve for x: 5 x+4 = 4+ 3 x−2 .

Answer

x≠−4,2; x= −5 2 ,1

2.T-11 §2.T source ↗

Solve for x. Write the answer in simplest radical form.

x 2 3 −x=- 1 2

Answer

x= 3± 3 2

2.T-13 §2.T source ↗

Solve: |2x+ 3|< 5.

Answer

( −4,1 )

2.T-15 §2.T source ↗

For the following exercises, find the equation of the line with the given information.

Passes through the points ( −4,2 ) and ( 5,−3 ).

Answer

y= −5 9 x− 2 9

2.T-17 §2.T source ↗

For the following exercises, find the equation of the line with the given information.

Passes through the point ( 2,1 ) and is perpendicular to y=− 2 5 x+3.

Answer

y= 5 2 x−4

2.T-19 §2.T source ↗

For the following exercises, find the equation of the line with the given information.

Simplify: −4 +3 −16 .

Answer

14i

2.T-21 §2.T source ↗

For the following exercises, find the equation of the line with the given information.

Divide: 4−i 2+3i .

Answer

5 13 − 14 13 i

2.T-23 §2.T source ↗

For the following exercises, find the equation of the line with the given information.

Solve: ( 3x−1 ) 2 − 1= 24.

Answer

x=2, −4 3

2.T-25 §2.T source ↗

For the following exercises, find the equation of the line with the given information.

Solve: 4 x 2 −4x−1=0

Answer

x= 1 2 ± 2 2

2.T-27 §2.T source ↗

For the following exercises, find the equation of the line with the given information.

Solve: 2+ 12−2x =x

Answer

4

2.T-29 §2.T source ↗

For the following exercises, find the real solutions of each equation by factoring.

2 x 3 − x 2 − 8x+ 4= 0

Answer

x= 1 2 ,2,−2

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Problems and answers are adapted from College Algebra 2e by Jay Abramson, OpenStax, and are used under the CC BY-NC-SA 4.0 licence. Access for free at https://openstax.org/books/college-algebra-2e/pages/1-introduction-to-prerequisites. Illustrations: Copyright Rice University, OpenStax, under CC BY-NC-SA 4.0 license. This adaptation is released under the same licence, is non-commercial, and is neither affiliated with nor endorsed by OpenStax or Rice University.