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2.8: Chapter 2 Review Exercises

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Chapter 2 Review Exercises

Solve Equations using the Subtraction and Addition Properties of Equality

Verify a Solution of an Equation

In the following exercises, determine whether each number is a solution to the equation.

Exercise 2.8.1

10x1=5x;x=15

Exercise 2.8.2

w+2=58;w=38

Answer

no

Exercise 2.8.3

12n+5=8n;n=54

Exercise 2.8.4

6a3=7a,a=313

Answer

yes

Solve Equations using the Subtraction and Addition Properties of Equality

In the following exercises, solve each equation using the Subtraction Property of Equality.

Exercise 2.8.5

x+7=19

Exercise 2.8.6

y+2=6

Answer

y=8

Exercise 2.8.7

a+13=53

Exercise 2.8.8

n+3.6=5.1

Answer

n=1.5

In the following exercises, solve each equation using the Addition Property of Equality.

Exercise 2.8.9

u7=10

Exercise 2.8.10

x9=4

Answer

x=5

Exercise 2.8.11

c311=911

Exercise 2.8.12

p4.8=14

Answer

p=18.8

In the following exercises, solve each equation.

Exercise 2.8.13

n12=32

Exercise 2.8.14

y+16=9

Answer

y=25

Exercise 2.8.15

f+23=4

Exercise 2.8.16

d3.9=8.2

Answer

d=12.1

Solve Equations That Require Simplification

In the following exercises, solve each equation.

Exercise 2.8.17

y+815=3

Exercise 2.8.18

7x+106x+3=5

Answer

x=8

Exercise 2.8.19

6(n1)5n=14

Exercise 2.8.20

8(3p+5)23(p1)=35

Answer

p=28

Translate to an Equation and Solve

In the following exercises, translate each English sentence into an algebraic equation and then solve it.

Exercise 2.8.21

The sum of 6 and m is 25

Exercise 2.8.22

Four less than n is 13

Answer

n4=13;n=17

Translate and Solve Applications

In the following exercises, translate into an algebraic equation and solve.

Exercise 2.8.23

Rochelle’s daughter is 11 years old. Her son is 3 years younger. How old is her son?

Exercise 2.8.24

Tan weighs 146 pounds. Minh weighs 15 pounds more than Tan. How much does Minh weigh?

Answer

161 pounds

Exercise 2.8.25

Peter paid $9.75 to go to the movies, which was $46.25 less than he paid to go to a concert. How much did he pay for the concert?

Exercise 2.8.26

Elissa earned $152.84 this week, which was $2..65 more than she earned last week. How much did she earn last week?

Answer

$131.19

Solve Equations using the Division and Multiplication Properties of Equality

Solve Equations Using the Division and Multiplication Properties of Equality

In the following exercises, solve each equation using the division and multiplication properties of equality and check the solution.

Exercise 2.8.27

8x=72

Exercise 2.8.28

13a=65

Answer

a=5

Exercise 2.8.29

0.25p=5.25

Exercise 2.8.30

y=4

Answer

y=4

Exercise 2.8.31

n6=18

Exercise 2.8.32

y10=30

Answer

y=300

Exercise 2.8.33

36=34x

Exercise 2.8.34

58u=1516

Answer

u=32

Exercise 2.8.35

18m=72

Exercise 2.8.36

c9=36

Answer

c=324

Exercise 2.8.37

0.45x=6.75

Exercise 2.8.38

1112=23y

Answer

y=118

Solve Equations That Require Simplification

In the following exercises, solve each equation requiring simplification.

Exercise 2.8.39

5r3r+9r=352

Exercise 2.8.40

24x+8x11x=714

Answer

x=1

Exercise 2.8.41

1112n56n=95

Exercise 2.8.42

9(d2)15=24

Answer

d=3

Translate to an Equation and Solve

In the following exercises, translate to an equation and then solve.

Exercise 2.8.43

143 is the product of 11 and y

Exercise 2.8.44

The quotient of b and and 9 is 27

Answer

b9=27;b=243

Exercise 2.8.45

The sum of q and one-fourth is one.

Exercise 2.8.46

The difference of s and one-twelfth is one fourth.

Answer

s112=14;s=13

Translate and Solve Applications

In the following exercises, translate into an equation and solve.

Exercise 2.8.47

Ray paid $21 for 12 tickets at the county fair. What was the price of each ticket?

Exercise 2.8.48

Janet gets paid $24 per hour. She heard that this is 34 of what Adam is paid. How much is Adam paid per hour?

Answer

$32

Solve Equations with Variables and Constants on Both Sides

Solve an Equation with Constants on Both Sides

In the following exercises, solve the following equations with constants on both sides.

Exercise 2.8.49

8p+7=47

Exercise 2.8.50

10w5=65

Answer

w=7

Exercise 2.8.51

3x+19=47

Exercise 2.8.52

32=49n

Answer

n=4

Solve an Equation with Variables on Both Sides

In the following exercises, solve the following equations with variables on both sides.

Exercise 2.8.53

7y=6y13

Exercise 2.8.54

5a+21=2a

Answer

a=7

Exercise 2.8.55

k=6k35

Exercise 2.8.56

4x38=3x

Answer

x=38

Solve an Equation with Variables and Constants on Both Sides

In the following exercises, solve the following equations with variables and constants on both sides.

Exercise 2.8.57

12x9=3x+45

Exercise 2.8.58

5n20=7n80

Answer

n=5

Exercise 2.8.59

4u+16=19u

Exercise 2.8.60

58c4=38c+4

Answer

c=32

Use a General Strategy for Solving Linear Equations

Solve Equations Using the General Strategy for Solving Linear Equations

In the following exercises, solve each linear equation.

Exercise 2.8.61

6(x+6)=24

Exercise 2.8.62

9(2p5)=72

Answer

p=132

Exercise 2.8.63

(s+4)=18

Exercise 2.8.64

8+3(n9)=17

Answer

n=12

Exercise 2.8.65

233(y7)=8

Exercise 2.8.66

13(6m+21)=m7

Answer

m=14

Exercise 2.8.67

4(3.5y+0.25)=365

Exercise 2.8.68

0.25(q8)=0.1(q+7)

Answer

q=18

Exercise 2.8.69

8(r2)=6(r+10)

Exercise 2.8.70

5+7(25x)=2(9x+1)(13x57)

Answer

x=1

Exercise 2.8.71

(9n+5)(3n7)=20(4n2)

Exercise 2.8.72

2[16+5(8k6)]=8(34k)32

Answer

k=34

Classify Equations

In the following exercises, classify each equation as a conditional equation, an identity, or a contradiction and then state the solution.

Exercise 2.8.73

17y3(42y)=11(y1)+12y1

Exercise 2.8.74

9u+32=15(u4)3(2u+21)

Answer

contradiction; no solution

Exercise 2.8.75

8(7m+4)=6(8m+9)

Exercise 2.8.76

21(c1)19(c+1)=2(c20)

Answer

identity; all real numbers

Solve Equations with Fractions and Decimals

Solve Equations with Fraction Coefficients

In the following exercises, solve each equation with fraction coefficients.

Exercise 2.8.77

25n110=710

Exercise 2.8.78

13x+15x=8

Answer

x=15

Exercise 2.8.79

34a13=12a56

Exercise 2.8.80

12(k3)=13(k+16)

Answer

k=41

Exercise 2.8.81

3x25=3x+48

Exercise 2.8.82

5y13+4=8y+46

Answer

y=1

Solve Equations with Decimal Coefficients

In the following exercises, solve each equation with decimal coefficients.

Exercise 2.8.83

0.8x0.3=0.7x+0.2

Exercise 2.8.84

0.36u+2.55=0.41u+6.8

Answer

u=85

Exercise 2.8.85

0.6p1.9=0.78p+1.7

Exercise 2.8.86

0.6p1.9=0.78p+1.7

Answer

d=20

Solve a Formula for a Specific Variable

Use the Distance, Rate, and Time Formula

In the following exercises, solve.

Exercise 2.8.87

Natalie drove for 712 hours at 60 miles per hour. How much distance did she travel?

Exercise 2.8.88

Mallory is taking the bus from St. Louis to Chicago. The distance is 300 miles and the bus travels at a steady rate of 60 miles per hour. How long will the bus ride be?

Answer

5 hours

Exercise 2.8.89

Aaron’s friend drove him from Buffalo to Cleveland. The distance is 187 miles and the trip took 2.75 hours. How fast was Aaron’s friend driving?

Exercise 2.8.90

Link rode his bike at a steady rate of 15 miles per hour for 212 hours. How much distance did he travel?

Answer

37.5 miles

Solve a Formula for a Specific Variable

In the following exercises, solve.

Exercise 2.8.91

Use the formula. d=rt to solve for t

  1. when d=510 and r=60
  2. in general
Exercise 2.8.92

Use the formula. d=rt to solve for r

  1. when when d=451 and t=5.5
  2. in general
Answer
  1. r=82mph
  2. r=Dt
Exercise 2.8.93

Use the formula A=12bh to solve for b

  1. when A=390 and h=26
  2. in general
Exercise 2.8.94

Use the formula A=12bh to solve for b

  1. when A=153 and b=18
  2. in general
Answer
  1. h=17
  2. h=2Ab
Exercise 2.8.95

Use the formula I=Prt to solve for the principal, P for

  1. I=$2,501,r=4.1%, t=5 years
  2. in general
Exercise 2.8.96

Solve the formula 4x+3y=6 for y

  1. when x=−2
  2. in general
Answer

y=143y=64x3

Exercise 2.8.97

Solve 180=a+b+c for c

Exercise 2.8.98

Solve the formula V=LWH for H

Answer

H=VLW

Solve Linear Inequalities

Graph Inequalities on the Number Line

In the following exercises, graph each inequality on the number line.

Exercise 2.8.99
  1. x4
  2. x>−2
  3. x<1
Exercise 2.8.100
  1. x>0
  2. x<−3
  3. x1
Answer
  1. This figure is a number line ranging from negative 5 to 5 with tick marks for each integer. The inequality x is greater than 0 is graphed on the number line, with an open parenthesis at x equals 0, and a dark line extending to the right of the parenthesis.
  2. This figure is a number line ranging from negative 5 to 5 with tick marks for each integer. The inequality x is less than negative 3 is graphed on the number line, with an open parenthesis at x equals negative 3, and a dark line extending to the left of the parenthesis.
  3. This figure is a number line ranging from negative 5 to 5 with tick marks for each integer. The inequality x is greater than or equal to 1 is graphed on the number line, with an open bracket at x equals 1, and a dark line extending to the right of the bracket.

In the following exercises, graph each inequality on the number line and write in interval notation.

Exercise 2.8.101
  1. x<1
  2. x2.5
  3. x54
Exercise 2.8.102
  1. x>2
  2. x1.5
  3. x53
Answer
  1. This figure is a number line ranging from negative 5 to 5 with tick marks for each integer. The inequality x is greater than 2 is graphed on the number line, with an open parenthesis at x equals 2, and a dark line extending to the right of the parenthesis. Below the number line is the solution written in interval notation: parenthesis, 2 comma infinity, parenthesis.
  2. This figure is a number line ranging from negative 5 to 5 with tick marks for each integer. The inequality x is less than or equal to negative 1.5 is graphed on the number line, with an open bracket at x equals negative 1.5, and a dark line extending to the left of the bracket. Below the number line is the solution written in interval notation: parenthesis, negative infinity comma negative 1.5, bracket.
  3. This figure is a number line ranging from negative 5 to 5 with tick marks for each integer. The inequality x is greater than or equal to 5/3 is graphed on the number line, with an open bracket at x equals 5/3, and a dark line extending to the right of the bracket. Below the number line is the solution written in interval notation: bracket, 5/3 comma infinity, parenthesis.

Solve Inequalities using the Subtraction and Addition Properties of Inequality

In the following exercises, solve each inequality, graph the solution on the number line, and write the solution in interval notation.

Exercise 2.8.103

n1223

Exercise 2.8.104

m+1456

Answer

At the top of this figure is the solution to the inequality: m is less than or equal to 42. Below this is a number line ranging from 40 to 44 with tick marks for each integer. The inequality m is less than or equal to 42 is graphed on the number line, with an open bracket at m equals 42, and a dark line extending to the left of the bracket. Below the number line is the solution written in interval notation: parenthesis, negative infinity comma 42, bracket

Exercise 2.8.105

a+23712

Exercise 2.8.106

b7812

Answer

At the top of this figure is the solution to the inequality: b is greater than or equal to 3/8. Below this is a number line ranging from negative 2 to 2 with tick marks for each integer. The inequality b is greater than or equal to 3/8 is graphed on the number line, with an open bracket at b equals 3/8 (written in), and a dark line extending to the right of the bracket. Below the number line is the solution written in interval notation: bracket, 3/8 comma infinity, bracket

Solve Inequalities using the Division and Multiplication Properties of Inequality

In the following exercises, solve each inequality, graph the solution on the number line, and write the solution in interval notation.

Exercise 2.8.107

9x>54

Exercise 2.8.108

12d108

Answer

At the top of this figure is the solution to the inequality: d is greater than or equal to negative 9. Below this is a number line ranging from negative 11 to negative 7 with tick marks for each integer. The inequality d is greater than or equal to negative 9 is graphed on the number line, with an open bracket at d equals negative 9, and a dark line extending to the right of the bracket. Below the number line is the solution written in interval notation: bracket, negative 9 comma infinity, parenthesis.

Exercise 2.8.109

52j<60

Exercise 2.8.110

q224

Answer

At the top of this figure is the solution to the inequality: q is less than or equal to 48. Below this is a number line ranging from 46 to 50 with tick marks for each integer. The inequality q is less than or equal to 48 is graphed on the number line, with an open bracket at q equals 48, and a dark line extending to the left of the bracket. Below the number line is the solution written in interval notation: parenthesis, negative infinity comma 48, bracket.

Solve Inequalities That Require Simplification

In the following exercises, solve each inequality, graph the solution on the number line, and write the solution in interval notation.

Exercise 2.8.111

6p>15p30

Exercise 2.8.112

9h7(h1)4h23

Answer

At the top of this figure is the solution to the inequality: h is greater than or equal to 15. Below this is a number line ranging from 13 to 17 with tick marks for each integer. The inequality h is greater than or equal to 15 is graphed on the number line, with an open bracket at h equals 15, and a dark line extending to the right of the bracket. Below the number line is the solution written in interval notation: bracket, 15 comma infinity, parenthesis.

Exercise 2.8.113

5n15(4n)<10(n6)+10n

Exercise 2.8.114

38a112a>512a+34

Answer

At the top of this figure is the solution to the inequality: a is less than negative 6. Below this is a number line ranging from negative 8 to negative 4 with tick marks for each integer. The inequality a is less than negative 6 is graphed on the number line, with an open parenthesis at a equals negative 6, and a dark line extending to the left of the parenthesis. Below the number line is the solution written in interval notation: parenthesis, negative infinity comma negative 6, parenthesis.

Translate to an Inequality and Solve

In the following exercises, translate and solve. Then write the solution in interval notation and graph on the number line.

Exercise 2.8.115

Five more than z is at most 19.

Exercise 2.8.116

Three less than c is at least 360.

Answer

At the top of this figure is the inequality c minus 3 is greater than or equal to 360. To the right of this is the solution to the inequality: c is greater than or equal to 363. To the right of the solution is the solution written in interval notation: bracket, 363 comma infinity, parenthesis. Below all of this is a number line ranging from 361 to 365 with tick marks for each integer. The inequality c is greater than or equal to 363 is graphed on the number line, with an open bracket at c equals 363, and a dark line extending to the right of the bracket.

Exercise 2.8.117

Nine times n exceeds 42.

Exercise 2.8.118

Negative two times a is no more than 8.

Answer

At the top of this figure is the inequality negative 2a is less than or equal to 8. To the right of this is the solution to the inequality: a is greater than or equal to negative 4. To the right of the solution is the solution written in interval notation: bracket, negative 4 comma infinity, parenthesis. Below all of this is a number line ranging from negative 6 to negative 2 with tick marks for each integer. The inequality a is greater than or equal to negative 4 is graphed on the number line, with an open bracket at a equals negative 4, and a dark line extending to the right of the bracket.

Everyday Math

Exercise 2.8.119

Describe how you have used two topics from this chapter in your life outside of your math class during the past month.

Chapter 2 Practice Test

Exercise 2.8.1

Determine whether each number is a solution to the equation 6x3=x+20

  1. 5
  2. 235
Answer
  1. no
  2. yes

In the following exercises, solve each equation.

Exercise 2.8.2

n23=14

Exercise 2.8.3

92c=144

Answer

c=32

Exercise 2.8.4

4y8=16

Exercise 2.8.5

8x15+9x1=21

Answer

x=5

Exercise 2.8.6

15a=120

Exercise 2.8.7

23x=6

Answer

x=9

Exercise \PageIndex{8}

x-3.8=8.2

Exercise \PageIndex{9}

10 y=-5 y-60

Answer

y=-4

Exercise \PageIndex{10}

8 n-2=6 n-12

Exercise \PageIndex{11}

9 m-2-4 m-m=42-8

Answer

m=9

Exercise \PageIndex{12}

-5(2 x-1)=45

Exercise \PageIndex{13}

-(d-9)=23

Answer

d=-14

Exercise \PageIndex{14}

\frac{1}{4}(12 m-28)=6-2(3 m-1)

Exercise \PageIndex{15}

2(6 x-5)-8=-22

Answer

x=-\frac{1}{3}

Exercise \PageIndex{16}

8(3 a-5)-7(4 a-3)=20-3 a

Exercise \PageIndex{17}

\frac{1}{4} p-\frac{1}{3}=\frac{1}{2}

Answer

p=\frac{10}{3}

Exercise \PageIndex{18}

0.1 d+0.25(d+8)=4.1

Exercise \PageIndex{19}

14 n-3(4 n+5)=-9+2(n-8)

Answer

contradiction; no solution

Exercise \PageIndex{20}

9(3 u-2)-4[6-8(u-1)]=3(u-2)

Exercise \PageIndex{21}

Solve the formula x−2y=5 for y

  1. when x=−3
  2. in general
Answer
  1. y=4
  2. y=\frac{5-x}{2}

In the following exercises, graph on the number line and write in interval notation.

Exercise \PageIndex{22}

x \geq-3.5

Exercise \PageIndex{23}

x<\frac{11}{4}

Answer

This figure is a number line ranging from 1 to 5 with tick marks for each integer. The inequality x is less than 11/4 is graphed on the number line, with an open parenthesis at x equals 11/4, and a dark line extending to the left of the parenthesis. Below the number line is the solution written in interval notation: parenthesis, negative infinity comma 11/4, parenthesis.

In the following exercises,, solve each inequality, graph the solution on the number line, and write the solution in interval notation.

Exercise \PageIndex{24}

8 k \geq 5 k-120

Exercise \PageIndex{25}

3 c-10(c-2)<5 c+16

Answer

This figure is a number line ranging from negative 2 to 3 with tick marks for each integer. The inequality c is greater than 1/3 is graphed on the number line, with an open parenthesis at c equals 1/3, and a dark line extending to the right of the parenthesis. Below the number line is the solution: c is greater than 1/3. To the right of the solution is the solution written in interval notation: parenthesis, 1/3 comma infinity, parenthesis

In the following exercises, translate to an equation or inequality and solve.

Exercise \PageIndex{26}

4 less than twice x is 16.

Exercise \PageIndex{27}

Fifteen more than n is at least 48.

Answer

n+15 \geq 48 ; n \geq 33

Exercise \PageIndex{28}

Samuel paid $25.82 for gas this week, which was $3.47 less than he paid last week. How much had he paid last week?

Exercise \PageIndex{29}

Jenna bought a coat on sale for \$ 120, which was \frac{2}{3} of the original price. What was the original price of the coat?

Answer

120=\frac{2}{3} p ; The original price was \$ 180

Exercise \PageIndex{30}

Sean took the bus from Seattle to Boise, a distance of 506 miles. If the trip took 7\frac{2}{3} hours, what was the speed of the bus?


This page titled 2.8: Chapter 2 Review Exercises is shared under a CC BY license and was authored, remixed, and/or curated by OpenStax.

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