Year 8 Substitution Worksheet — Level 3 — Practice Set 2 — Answers
Answer sheet with worked solutions for the Year 8 algebraic expressions worksheet.
Success TutoringWorksheetsAnswer sheetYear 8 · Mathematics · Algebraic ExpressionsYear 8 Substitution Worksheet — Level 3 — Practice Set 2 — Answers
Replace the letter with the number, then calculate. Use brackets for negative values.
1.Find the value of −3x + 1 when x = 2
Answer: −5
- −3 × 2 + 1
- = −6 + 1 = −5
2.Find the value of −4x − 9 when x = 1
Answer: −13
- −4 × 1 − 9
- = −4 − 9 = −13
3.If x = −6 and y = −2, find the value of −4x2 + 0
Answer: −144
- −4 × (−6)² + 0 × (−2)
- = −144 + 0 = −144
4.Find the value of −2x − 1 when x = 9
Answer: −19
- −2 × 9 − 1
- = −18 − 1 = −19
5.If x = 6 and y = 3, find the value of −x2 + 5y
Answer: −21
- −1 × (6)² + 5 × (3)
- = −36 + 15 = −21
6.Find the value of x − 2 when x = −1
Answer: −3
- 1 × (−1) − 2
- = −1 − 2 = −3
7.If x = 5 and y = −1, find the value of 5x2 − 5y
Answer: 130
- 5 × (5)² − 5 × (−1)
- = 125 + 5 = 130
8.If x = −3 and y = 6, find the value of 7x2 − y
Answer: 57
- 7 × (−3)² − 1 × (6)
- = 63 − 6 = 57
9.If x = −6 and y = −4, find the value of 4x2 − 3y
Answer: 156
- 4 × (−6)² − 3 × (−4)
- = 144 + 12 = 156
10.If x = −6 and y = 1, find the value of −x2 + 5y
Answer: −31
- −1 × (−6)² + 5 × (1)
- = −36 + 5 = −31
11.Find the value of −5x + 4 when x = −4
Answer: 24
- −5 × (−4) + 4
- = 20 + 4 = 24
12.If x = 5 and y = 3, find the value of −4x2 − 3y
Answer: −109
- −4 × (5)² − 3 × (3)
- = −100 − 9 = −109
Marking tips
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