Year 9 Substitution Worksheet — Level 3 — Practice Set 2 — Answers
Answer sheet with worked solutions for the Year 9 algebraic expressions worksheet.
Success TutoringWorksheetsAnswer sheetYear 9 · Mathematics · Algebraic ExpressionsYear 9 Substitution Worksheet — Level 3 — Practice Set 2 — Answers
Replace the letter with the number, then calculate. Use brackets for negative values.
1.If x = 2 and y = 5, find the value of −5x2 − 6y
Answer: −50
- −5 × (2)² − 6 × (5)
- = −20 − 30 = −50
2.Find the value of 7x − 7 when x = −6
Answer: −49
- 7 × (−6) − 7
- = −42 − 7 = −49
3.Find the value of −3x − 1 when x = −2
Answer: 5
- −3 × (−2) − 1
- = 6 − 1 = 5
4.Find the value of 5x + 8 when x = 3
Answer: 23
- 5 × 3 + 8
- = 15 + 8 = 23
5.If x = 8 and y = 6, find the value of 9x2 + 5y
Answer: 606
- 9 × (8)² + 5 × (6)
- = 576 + 30 = 606
6.If x = 6 and y = 1, find the value of 5x2 − 3y
Answer: 177
- 5 × (6)² − 3 × (1)
- = 180 − 3 = 177
7.Find the value of 7x − 9 when x = 9
Answer: 54
- 7 × 9 − 9
- = 63 − 9 = 54
8.If x = 1 and y = −2, find the value of −5x2 − 8y
Answer: 11
- −5 × (1)² − 8 × (−2)
- = −5 + 16 = 11
9.Find the value of 7x − 9 when x = 6
Answer: 33
- 7 × 6 − 9
- = 42 − 9 = 33
10.If x = −1 and y = 5, find the value of 3x2 − 9y
Answer: −42
- 3 × (−1)² − 9 × (5)
- = 3 − 45 = −42
11.Find the value of 3x + 9 when x = 5
Answer: 24
- 3 × 5 + 9
- = 15 + 9 = 24
12.If x = −5 and y = 4, find the value of x2 − 5y
Answer: 5
- 1 × (−5)² − 5 × (4)
- = 25 − 20 = 5
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