Year 8 Substitution Worksheet — Level 3 — Practice Set 4 — 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 4 — Answers
Replace the letter with the number, then calculate. Use brackets for negative values.
1.Find the value of 9x − 3 when x = −3
Answer: −30
- 9 × (−3) − 3
- = −27 − 3 = −30
2.Find the value of −5x + 6 when x = 3
Answer: −9
- −5 × 3 + 6
- = −15 + 6 = −9
3.If x = −6 and y = 6, find the value of 7x2 + 3y
Answer: 270
- 7 × (−6)² + 3 × (6)
- = 252 + 18 = 270
4.Find the value of 2x + 4 when x = 5
Answer: 14
- 2 × 5 + 4
- = 10 + 4 = 14
5.Find the value of −2x − 4 when x = −2
Answer: 0
- −2 × (−2) − 4
- = 4 − 4 = 0
6.If x = 7 and y = 2, find the value of 5x2 + 2y
Answer: 249
- 5 × (7)² + 2 × (2)
- = 245 + 4 = 249
7.Find the value of −3x − 9 when x = −5
Answer: 6
- −3 × (−5) − 9
- = 15 − 9 = 6
8.Find the value of −3x − 8 when x = 7
Answer: −29
- −3 × 7 − 8
- = −21 − 8 = −29
9.Find the value of −3x + 4 when x = −6
Answer: 22
- −3 × (−6) + 4
- = 18 + 4 = 22
10.If x = 5 and y = −4, find the value of 5x2 + 6y
Answer: 101
- 5 × (5)² + 6 × (−4)
- = 125 − 24 = 101
11.If x = 1 and y = 1, find the value of −2x2 + y
Answer: −1
- −2 × (1)² + 1 × (1)
- = −2 + 1 = −1
12.Find the value of 4x − 6 when x = −5
Answer: −26
- 4 × (−5) − 6
- = −20 − 6 = −26
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