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8th Grade Substitution Worksheet — Level 3 — 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 — Answers

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

1.If x = −1 and y = 2, find the value of 2x2 − 9y

Answer: −16

  1. 2 × (−1)² − 9 × (2)
  2. = 2 − 18 = −16
2.Find the value of 8x when x = −2

Answer: −16

  1. 8 × (−2) + 0
  2. = −16 + 0 = −16
3.Find the value of 5x + 6 when x = 4

Answer: 26

  1. 5 × 4 + 6
  2. = 20 + 6 = 26
4.If x = 1 and y = −3, find the value of x2 − 9y

Answer: 28

  1. 1 × (1)² − 9 × (−3)
  2. = 1 + 27 = 28
5.Find the value of 2x + 3 when x = 2

Answer: 7

  1. 2 × 2 + 3
  2. = 4 + 3 = 7
6.Find the value of −5x + 3 when x = 8

Answer: −37

  1. −5 × 8 + 3
  2. = −40 + 3 = −37
7.If x = 8 and y = −3, find the value of 9x2 + 6y

Answer: 558

  1. 9 × (8)² + 6 × (−3)
  2. = 576 − 18 = 558
8.Find the value of −2x − 8 when x = −4

Answer: 0

  1. −2 × (−4) − 8
  2. = 8 − 8 = 0
9.Find the value of 4x − 5 when x = 4

Answer: 11

  1. 4 × 4 − 5
  2. = 16 − 5 = 11
10.Find the value of 4x + 9 when x = 5

Answer: 29

  1. 4 × 5 + 9
  2. = 20 + 9 = 29
11.If x = −2 and y = 3, find the value of −3x2 + y

Answer: −9

  1. −3 × (−2)² + 1 × (3)
  2. = −12 + 3 = −9
12.Find the value of 2x − 3 when x = 3

Answer: 3

  1. 2 × 3 − 3
  2. = 6 − 3 = 3
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