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 = 5 and y = −2, find the value of x2 − 2y
Answer: 29
- 1 × (5)² − 2 × (−2)
- = 25 + 4 = 29
2.Find the value of −5x + 7 when x = 6
Answer: −23
- −5 × 6 + 7
- = −30 + 7 = −23
3.If x = −3 and y = 2, find the value of −4x2 + 6y
Answer: −24
- −4 × (−3)² + 6 × (2)
- = −36 + 12 = −24
4.If x = 5 and y = −1, find the value of −5x2 − 5y
Answer: −120
- −5 × (5)² − 5 × (−1)
- = −125 + 5 = −120
5.Find the value of 4x − 1 when x = 3
Answer: 11
- 4 × 3 − 1
- = 12 − 1 = 11
6.Find the value of −2x − 2 when x = 6
Answer: −14
- −2 × 6 − 2
- = −12 − 2 = −14
7.Find the value of −5x + 4 when x = 9
Answer: −41
- −5 × 9 + 4
- = −45 + 4 = −41
8.If x = 2 and y = −3, find the value of −3x2 − 3y
Answer: −3
- −3 × (2)² − 3 × (−3)
- = −12 + 9 = −3
9.If x = 9 and y = 5, find the value of −4x2 + 7y
Answer: −289
- −4 × (9)² + 7 × (5)
- = −324 + 35 = −289
10.If x = 6 and y = 3, find the value of −5x2 − y
Answer: −183
- −5 × (6)² − 1 × (3)
- = −180 − 3 = −183
11.Find the value of 2x + 3 when x = 2
Answer: 7
- 2 × 2 + 3
- = 4 + 3 = 7
12.If x = −6 and y = 4, find the value of −2x2 − 3y
Answer: −84
- −2 × (−6)² − 3 × (4)
- = −72 − 12 = −84
Marking tips
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