Answer Key
Chapter 7 – Equations, Inequalities and Functions 7.1
Addition and Subtraction Phrases as Equations
Answers 1. x + 5
2. x + 6
3. y + 8
4. n – 7
5. 8 – 4
6. n + 9
7. n – 5 = 10
8. 8 – 4 = x
9. 5 + y = 12
10. x – 16 = 80
11. 20 + x = 55
12. x + 15 = 40
13. n + 12 = 60
14. n – 15 = 90
15. x – 60 = 80
7.2
Multiplication and Division Phrases as Equations
Answers 1. 4x = 12
2. 6x = 30
3. 12y = 48
4. 14x = 28
5. 5y = 30
6. 8x = 64
7. 20/y = 4
8. 80/x = 4
9. 19x = 95
10. 13y = 39
11. 12/x = 6
12. x/2 = 8
13. x/7 = 14
14. 5x = 35
15. x/12 = 12
7.3
Single Variable Equations from Verbal Models
Answers 1. 10x = 30
2. 5x = 15
3. x + 7 = 11
4. x/3 = 12
5. x + 18 = 30
6. x/12 = 14
7. 7y = 49
8. x/13 = 7
9. 8y = 64
10. j – 8
11. c/3
12. 2s
13. w + 3 = l
14. n/3 = 6
15. 30 – 20 = c
7.4
Simplify Sums or Differences of Single Variable Expressions
Answers 1. 13a
2. 5x
3. 18y
4. 20a
5. 5y
6. 23a
7. 4b
8. 41x
9. 33y
10. 43a
11. 10x
12. 20a
13. 54b
14. 83x
15. 44y
CK-12 Middle School Math Concepts - Grade 7
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Answer Key
Chapter 7 – Equations, Inequalities and Functions 7.5
Simplify Products or Quotients of Single Variable Expressions
Answers 1. 24a2
2. 18x
3. 28y2
4. 16a2
5. 44x2
6. 36b
7. 3a
8. 11
9. 25
10. 9
11. 5
12. 2y
13. 2
14. 5x/y
7.6
15. 41
Simplify Variable Expressions Involving Multiple Operations
Answers 1. 10a – 2b
2. 24b
3. 25a
4. 9x
6. 12a – 12b
7. 40a + 14b
8. 40a + 3b
9. 22a + 12y
10. 80a + 2b
11. 20y – 2x
12. 12x + 4y – 19z
13. 20y
14. 35y
15. 52y
7.7
5. 10y
Single Variable Addition Equations
Answers 1. 7
2. 17
3. 7
4. 17
5. 8
6. 6
7. 36
8. 35
9. 21
10. 226
13. 308
14. 8
15. 236
11. 226
7.8
12. 206
Single Variable Subtraction Equations
Answers 1. 17
2. 47
3. 38
4. 34
5. 41
6. 63
7. 80
8. 42
9. 41
10. 51
11. 5.1
12. 7.4
13. 15.6
14. 4.77
15. 14.64
CK-12 Middle School Math Concepts - Grade 7
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Chapter 7 – Equations, Inequalities and Functions 7.9
Answer Key
Single Variable Multiplication Equations
Answers 1. 4
2. 12
3. -12
4. -8
5. 8
6. 9
7. -2
8. 2
9. -7
10. -3
11. -2
12. 2
13. -3
14. 3
15. 3
7.10
Single Variable Division Equations
Answers 1. 10
2. 21
6. 30
11. -40
7.11
3. -36
4. -80
5. 160
7. -360
8. 81
9. -132
10. -9
12. 3.9
13. 9.6
14. 7.2
15. 4.5
Two Step Equations from Verbal Models
Answers 1. 2x + 7 = 19
2. 3x + 5 = 20
3. 6x + 10 = 46
4. 2x – 7 = 21
5. 3x – 8 = 16
6. x/2 + 7 = 10
7. x/3 + 6 = 11
8. x/4 – 2 = 10
9. 4x + 8 = 20
10. 5x – 3 = 12
11. 2x + 7 = 29
12. 4x + 2 = 26
13. -3x – 4 = -10
14. -2x + 8 = -12
15. -5x – 8 = 17
7.12
Two – Step Equations and Properties of Equality
Answers 1. 4
2. 4
3. 3
4. 7
5. 7
6. 9
7. 4
8. 2
9. 6
10. 10
11. 9
12. 7
13. 7
14. 2m – 7 = 3, Monday = 5 shirts
15. 19 = 1/2r + 6, red = 26
CK-12 Middle School Math Concepts - Grade 7
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Chapter 7 – Equations, Inequalities and Functions 7.13
Answer Key
Inequalities on a Number Line
Answers 1.
2.
3.
4.
5.
6.
7.
8.
CK-12 Middle School Math Concepts - Grade 7
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Chapter 7 – Equations, Inequalities and Functions
Answer Key
9.
10.
11.
12.
13.
14.
15.
CK-12 Middle School Math Concepts - Grade 7
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Answer Key
Chapter 7 – Equations, Inequalities and Functions 7.14
One – Step Inequalities
Answers 1. x < 6
2. x ≥ 10
3. b ≤ 10
4. a ≥ 21
5. y > 5
6. x ≤ 3
7. y > 3
8. x > 4
9. x = 20
10. x ≤ 30
11. x ≥ 1
12. y ≤ 2
13. a > 6
14. b < 15
15. x < 25
7.15
Domain and Range of a Function
Answers 1. No
2. Yes
3. Yes
4. No
5. No
6. {1, 2, 2, 3}
7. {2, 3, 4, 5}
8. {6, 7, 8}
9. {5}
10. {81, 75, 76, 77}
11. {3, 6, 5, 7}
12. {5, 6, 7, 8}
13. {1, 2, 3}
14. {2, 3, 4, 5}
15. {19, 18}
7.16
Input – Output Tables for Function Rules
Answers 1. (0, 2)(1, 9)(2, 16)(3, 23)(4, 30)
2. (0,-6)(6,0)(13,7)(22,16)
3. (8,3)(14, 6)
4. No
5. Yes
6. No
7. Yes
8. Yes
9. Yes
10. Yes
11 – 15 Answers Vary
7.17
Function Rules for Input-Output Tables
Answers 1. Add 2 each time
2. y = x + 2
3. Multiply by 2
4. y = 2x
5. Multiply by 2 and add 1
6. y = 2x + 1
7. 48, 60
8. Multiply by 12
9. y = 12x
10. 60
11. (0, 10)(1, 30)(2, 50)(3, 70)(4, 90) 12. {0, 1, 2, 3, 4} 13. Zero doesn’t make sense because it isn’t a row 14. Add 3 15. y = x + 3
CK-12 Middle School Math Concepts - Grade 7
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Answer Key
Chapter 7 – Equations, Inequalities and Functions 7.18
Graphs of Linear Equations
Answers 1. y = x + 3
2. y = 2x
CK-12 Middle School Math Concepts - Grade 7
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Answer Key
Chapter 7 – Equations, Inequalities and Functions 3. y = 3x
4. y = x – 2
CK-12 Middle School Math Concepts - Grade 7
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Answer Key
Chapter 7 – Equations, Inequalities and Functions 5. y = x + 4
6. y = 7x
CK-12 Middle School Math Concepts - Grade 7
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Answer Key
Chapter 7 – Equations, Inequalities and Functions 7. y = 2x + 1
8. y = 2x – 1
CK-12 Middle School Math Concepts - Grade 7
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Answer Key
Chapter 7 – Equations, Inequalities and Functions 9. y = 3x – 1
10. y = 4x
CK-12 Middle School Math Concepts - Grade 7
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Answer Key
Chapter 7 – Equations, Inequalities and Functions 7.19
Linear and Non – Linear Function Distribution
Answers 1. Non Linear
2. Linear
4. Missing a table
5. Can’t answer – missing information
3. Non linear
6. (-4, 2)(-2, 3)(0, 4)(2, 5)(4, 6) 7.
8. Linear 9. (-2, 6)(-1, 3)(0, 2)(1, 3)(2, 6) 10.
11. Non Linear
CK-12 Middle School Math Concepts - Grade 7
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Chapter 7 – Equations, Inequalities and Functions
Answer Key
12. y = x + 1 13.
14. y = 2x – 2 15.
CK-12 Middle School Math Concepts - Grade 7
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Answer Key
Chapter 7 – Equations, Inequalities and Functions 7.20
Linear and Non – Linear Patterns of Change
Answers 1. Non-Linear
2. Linear
3. Linear
4. Linear
5. Non-Linear
6. Linear
7. Linear
8. Non-Linear
9. Linear
10. Non-Linear
11. y = 3x 12.
13. $9.00 14. (0, 10)(1, 8)(2, 6)(3, 4) 15.
16. $2.00
CK-12 Middle School Math Concepts - Grade 7
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