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8th Grade Substitution Worksheet — Level 3 — Practice Set 4 — 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 4 — Answers

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

1.Find the value of 4x + 8 when x = −4

Answer: −8

  1. 4 × (−4) + 8
  2. = −16 + 8 = −8
2.If x = −6 and y = −4, find the value of −5x2 − 5y

Answer: −160

  1. −5 × (−6)² − 5 × (−4)
  2. = −180 + 20 = −160
3.If x = 5 and y = 5, find the value of −2x2 + 0

Answer: −50

  1. −2 × (5)² + 0 × (5)
  2. = −50 + 0 = −50
4.If x = 7 and y = 6, find the value of −2x2 − 3y

Answer: −116

  1. −2 × (7)² − 3 × (6)
  2. = −98 − 18 = −116
5.If x = −6 and y = 5, find the value of −5x2 + y

Answer: −175

  1. −5 × (−6)² + 1 × (5)
  2. = −180 + 5 = −175
6.If x = 9 and y = −4, find the value of −5x2 + 7y

Answer: −433

  1. −5 × (9)² + 7 × (−4)
  2. = −405 − 28 = −433
7.Find the value of 4x − 9 when x = 1

Answer: −5

  1. 4 × 1 − 9
  2. = 4 − 9 = −5
8.If x = −1 and y = 4, find the value of 3x2 + 0

Answer: 3

  1. 3 × (−1)² + 0 × (4)
  2. = 3 + 0 = 3
9.Find the value of 3x − 3 when x = −6

Answer: −21

  1. 3 × (−6) − 3
  2. = −18 − 3 = −21
10.If x = −2 and y = −4, find the value of −x2 − 7y

Answer: 24

  1. −1 × (−2)² − 7 × (−4)
  2. = −4 + 28 = 24
11.Find the value of −x − 4 when x = 1

Answer: −5

  1. −1 × 1 − 4
  2. = −1 − 4 = −5
12.If x = 7 and y = 2, find the value of −5x2 + y

Answer: −243

  1. −5 × (7)² + 1 × (2)
  2. = −245 + 2 = −243
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