Year 8 Substitution Worksheet — Level 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 — Answers
Replace the letter with the number, then calculate. Use brackets for negative values.
1.Find the value of −2x − 6 when x = −3
Answer: 0
- −2 × (−3) − 6
- = 6 − 6 = 0
2.Find the value of 4x + 4 when x = 2
Answer: 12
- 4 × 2 + 4
- = 8 + 4 = 12
3.Find the value of −2x − 4 when x = 7
Answer: −18
- −2 × 7 − 4
- = −14 − 4 = −18
4.Find the value of −5x + 2 when x = 9
Answer: −43
- −5 × 9 + 2
- = −45 + 2 = −43
5.If x = 7 and y = 6, find the value of −2x2 + 2y
Answer: −86
- −2 × (7)² + 2 × (6)
- = −98 + 12 = −86
6.If x = 3 and y = −5, find the value of 8x2 − 7y
Answer: 107
- 8 × (3)² − 7 × (−5)
- = 72 + 35 = 107
7.If x = −5 and y = 6, find the value of −2x2 + 8y
Answer: −2
- −2 × (−5)² + 8 × (6)
- = −50 + 48 = −2
8.If x = 2 and y = −5, find the value of 4x2 + 7y
Answer: −19
- 4 × (2)² + 7 × (−5)
- = 16 − 35 = −19
9.If x = −2 and y = −4, find the value of −2x2 − 5y
Answer: 12
- −2 × (−2)² − 5 × (−4)
- = −8 + 20 = 12
10.Find the value of 9x + 7 when x = 6
Answer: 61
- 9 × 6 + 7
- = 54 + 7 = 61
11.If x = −2 and y = 1, find the value of −x2 − 3y
Answer: −7
- −1 × (−2)² − 3 × (1)
- = −4 − 3 = −7
12.Find the value of −x − 5 when x = 3
Answer: −8
- −1 × 3 − 5
- = −3 − 5 = −8
Marking tips
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