Year 7 Substitution Worksheet — Level 3 — Practice Set 4 — Answers
Answer sheet with worked solutions for the Year 7 algebraic expressions worksheet.
Success TutoringWorksheetsAnswer sheetYear 7 · Mathematics · Algebraic ExpressionsYear 7 Substitution Worksheet — Level 3 — Practice Set 4 — Answers
Replace the letter with the number, then calculate. Use brackets for negative values.
1.If x = 9 and y = −2, find the value of −3x2 + 3y
Answer: −249
- −3 × (9)² + 3 × (−2)
- = −243 − 6 = −249
2.If x = 4 and y = 2, find the value of 8x2 + 5y
Answer: 138
- 8 × (4)² + 5 × (2)
- = 128 + 10 = 138
3.If x = 5 and y = −4, find the value of 6x2 − 5y
Answer: 170
- 6 × (5)² − 5 × (−4)
- = 150 + 20 = 170
4.Find the value of 5x − 7 when x = 5
Answer: 18
- 5 × 5 − 7
- = 25 − 7 = 18
5.If x = −6 and y = −3, find the value of 2x2 + 7y
Answer: 51
- 2 × (−6)² + 7 × (−3)
- = 72 − 21 = 51
6.If x = −1 and y = 5, find the value of 8x2 + 9y
Answer: 53
- 8 × (−1)² + 9 × (5)
- = 8 + 45 = 53
7.Find the value of 3x + 4 when x = −2
Answer: −2
- 3 × (−2) + 4
- = −6 + 4 = −2
8.If x = 5 and y = −1, find the value of −x2 − 8y
Answer: −17
- −1 × (5)² − 8 × (−1)
- = −25 + 8 = −17
9.If x = 5 and y = −2, find the value of 5x2 + 6y
Answer: 113
- 5 × (5)² + 6 × (−2)
- = 125 − 12 = 113
10.If x = 5 and y = −3, find the value of 6x2 − y
Answer: 153
- 6 × (5)² − 1 × (−3)
- = 150 + 3 = 153
11.Find the value of 3x + 7 when x = 4
Answer: 19
- 3 × 4 + 7
- = 12 + 7 = 19
12.If x = 3 and y = 3, find the value of 3x2 + 6y
Answer: 45
- 3 × (3)² + 6 × (3)
- = 27 + 18 = 45
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