Year 8 Substitution Worksheet — Level 3 — Practice Set 3 — 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 3 — Answers
Replace the letter with the number, then calculate. Use brackets for negative values.
1.If x = −3 and y = 5, find the value of 9x2 + 5y
Answer: 106
- 9 × (−3)² + 5 × (5)
- = 81 + 25 = 106
2.If x = 1 and y = 2, find the value of −3x2 + 0
Answer: −3
- −3 × (1)² + 0 × (2)
- = −3 + 0 = −3
3.Find the value of −3x − 3 when x = 2
Answer: −9
- −3 × 2 − 3
- = −6 − 3 = −9
4.If x = −1 and y = 1, find the value of −2x2 − 5y
Answer: −7
- −2 × (−1)² − 5 × (1)
- = −2 − 5 = −7
5.Find the value of 2x + 7 when x = 2
Answer: 11
- 2 × 2 + 7
- = 4 + 7 = 11
6.Find the value of 4x − 2 when x = 4
Answer: 14
- 4 × 4 − 2
- = 16 − 2 = 14
7.Find the value of 8x − 4 when x = 7
Answer: 52
- 8 × 7 − 4
- = 56 − 4 = 52
8.Find the value of −3x − 9 when x = −1
Answer: −6
- −3 × (−1) − 9
- = 3 − 9 = −6
9.Find the value of 5x − 2 when x = 3
Answer: 13
- 5 × 3 − 2
- = 15 − 2 = 13
10.Find the value of −4x + 6 when x = 6
Answer: −18
- −4 × 6 + 6
- = −24 + 6 = −18
11.If x = 2 and y = −2, find the value of −4x2 + 7y
Answer: −30
- −4 × (2)² + 7 × (−2)
- = −16 − 14 = −30
12.Find the value of −x − 6 when x = 9
Answer: −15
- −1 × 9 − 6
- = −9 − 6 = −15
Marking tips
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