Year 7 Substitution Worksheet — Level 3 — Practice Set 3 — 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 3 — Answers
Replace the letter with the number, then calculate. Use brackets for negative values.
1.Find the value of −2x + 5 when x = 8
Answer: −11
- −2 × 8 + 5
- = −16 + 5 = −11
2.If x = 1 and y = 1, find the value of −3x2 + 0
Answer: −3
- −3 × (1)² + 0 × (1)
- = −3 + 0 = −3
3.If x = 1 and y = −4, find the value of 5x2 − 2y
Answer: 13
- 5 × (1)² − 2 × (−4)
- = 5 + 8 = 13
4.Find the value of −3x when x = 5
Answer: −15
- −3 × 5 + 0
- = −15 + 0 = −15
5.If x = −2 and y = 4, find the value of 9x2 − 7y
Answer: 8
- 9 × (−2)² − 7 × (4)
- = 36 − 28 = 8
6.If x = 3 and y = −3, find the value of 5x2 + 4y
Answer: 33
- 5 × (3)² + 4 × (−3)
- = 45 − 12 = 33
7.If x = 7 and y = −3, find the value of 8x2 + 8y
Answer: 368
- 8 × (7)² + 8 × (−3)
- = 392 − 24 = 368
8.Find the value of 2x − 8 when x = 3
Answer: −2
- 2 × 3 − 8
- = 6 − 8 = −2
9.Find the value of 2x − 4 when x = 8
Answer: 12
- 2 × 8 − 4
- = 16 − 4 = 12
10.If x = 7 and y = −3, find the value of 4x2 − 3y
Answer: 205
- 4 × (7)² − 3 × (−3)
- = 196 + 9 = 205
11.Find the value of x − 3 when x = −6
Answer: −9
- 1 × (−6) − 3
- = −6 − 3 = −9
12.If x = 5 and y = −2, find the value of −2x2 − 3y
Answer: −44
- −2 × (5)² − 3 × (−2)
- = −50 + 6 = −44
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