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8th Grade Substitution Worksheet — Level 3 — Practice Set 2 — Answers

Answer sheet with worked solutions for the 8th Grade algebraic expressions worksheet.

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Success TutoringWorksheetsAnswer sheet8th Grade · Mathematics · Algebraic Expressions

8th Grade Substitution Worksheet — Level 3 — Practice Set 2 — Answers

Replace the letter with the number, then calculate. Use parentheses for negative values.

1.Find the value of −x − 8 when x = 2

Answer: −10

  1. −1 × 2 − 8
  2. = −2 − 8 = −10
2.Find the value of 5x − 1 when x = −1

Answer: −6

  1. 5 × (−1) − 1
  2. = −5 − 1 = −6
3.If x = 3 and y = −4, find the value of −x2 + 8y

Answer: −41

  1. −1 × (3)² + 8 × (−4)
  2. = −9 − 32 = −41
4.Find the value of 2x − 1 when x = 4

Answer: 7

  1. 2 × 4 − 1
  2. = 8 − 1 = 7
5.Find the value of −2x + 9 when x = −6

Answer: 21

  1. −2 × (−6) + 9
  2. = 12 + 9 = 21
6.Find the value of 4x − 4 when x = −4

Answer: −20

  1. 4 × (−4) − 4
  2. = −16 − 4 = −20
7.Find the value of 5x + 7 when x = −4

Answer: −13

  1. 5 × (−4) + 7
  2. = −20 + 7 = −13
8.If x = 8 and y = −1, find the value of 7x2 − 2y

Answer: 450

  1. 7 × (8)² − 2 × (−1)
  2. = 448 + 2 = 450
9.If x = 1 and y = 6, find the value of −5x2 + 4y

Answer: 19

  1. −5 × (1)² + 4 × (6)
  2. = −5 + 24 = 19
10.If x = 4 and y = −2, find the value of −5x2 + 0

Answer: −80

  1. −5 × (4)² + 0 × (−2)
  2. = −80 + 0 = −80
11.If x = 7 and y = 6, find the value of 4x2 − 4y

Answer: 172

  1. 4 × (7)² − 4 × (6)
  2. = 196 − 24 = 172
12.If x = −5 and y = 4, find the value of 4x2 − 8y

Answer: 68

  1. 4 × (−5)² − 8 × (4)
  2. = 100 − 32 = 68
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