Year 9 Substitution Worksheet — Level 3 — Answers
Answer sheet with worked solutions for the Year 9 algebraic expressions worksheet.
Year 9 · Mathematics · Algebraic Expressions
Year 9 Substitution Worksheet — Level 3 — Answers
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Replace the letter with the number, then calculate. Use brackets for negative values.
1.Find the value of −3x + 6 when x = 5
Answer: −9
- −3 × 5 + 6
- = −15 + 6 = −9
2.Find the value of −3x − 3 when x = 2
Answer: −9
- −3 × 2 − 3
- = −6 − 3 = −9
3.If x = 6 and y = −5, find the value of −4x2 + 2y
Answer: −154
- −4 × (6)² + 2 × (−5)
- = −144 − 10 = −154
4.If x = 4 and y = 5, find the value of −3x2 + 2y
Answer: −38
- −3 × (4)² + 2 × (5)
- = −48 + 10 = −38
5.If x = 3 and y = −2, find the value of −2x2 + 2y
Answer: −22
- −2 × (3)² + 2 × (−2)
- = −18 − 4 = −22
6.If x = 2 and y = 2, find the value of −5x2 − 8y
Answer: −36
- −5 × (2)² − 8 × (2)
- = −20 − 16 = −36
7.Find the value of 9x − 7 when x = −6
Answer: −61
- 9 × (−6) − 7
- = −54 − 7 = −61
8.Find the value of 9x − 9 when x = −1
Answer: −18
- 9 × (−1) − 9
- = −9 − 9 = −18
9.Find the value of 9x − 5 when x = 3
Answer: 22
- 9 × 3 − 5
- = 27 − 5 = 22
10.Find the value of 4x + 5 when x = −6
Answer: −19
- 4 × (−6) + 5
- = −24 + 5 = −19
11.If x = 4 and y = 4, find the value of 2x2 − 7y
Answer: 4
- 2 × (4)² − 7 × (4)
- = 32 − 28 = 4
12.If x = −6 and y = 5, find the value of 6x2 + 7y
Answer: 251
- 6 × (−6)² + 7 × (5)
- = 216 + 35 = 251
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