9th Grade Factoring Expressions (Common Factors) Worksheet — Level 3 — Practice Set 4 — Answers
Answer sheet with worked solutions for the 9th Grade algebraic expressions worksheet.
9th Grade Factoring Expressions (Common Factors) Worksheet — Level 3 — Practice Set 4 — Answers
Take out the highest common factor. Where the first term is negative, take out a negative factor.
1.Factor fully: −2x + 16
Answer: −2(x − 8)
- Highest common factor: −2
- −2x + 16 = −2(x − 8)
- Check by expanding the parentheses.
2.Factor fully: 8x2 + 4x + 4
Answer: 4(2x2+x+1)
- Highest common factor: 4
- 8x2 + 4x + 4 = 4(2x2 + x + 1)
- Check by expanding the parentheses.
3.Factor fully: 3ab + 18a
Answer: 3a(b + 6)
- Highest common factor: 3a
- 3ab + 18a = 3a(b + 6)
- Check by expanding the parentheses.
4.Factor fully: −35x − 28
Answer: −7(5x + 4)
- Highest common factor: −7
- −35x − 28 = −7(5x + 4)
- Check by expanding the parentheses.
5.Factor fully: 9x2 + 9x + 24
Answer: 3(3x2+3x+8)
- Highest common factor: 3
- 9x2 + 9x + 24 = 3(3x2 + 3x + 8)
- Check by expanding the parentheses.
6.Factor fully: 24ab + 4a
Answer: 4a(6b + 1)
- Highest common factor: 4a
- 24ab + 4a = 4a(6b + 1)
- Check by expanding the parentheses.
7.Factor fully: −20x − 28
Answer: −4(5x + 7)
- Highest common factor: −4
- −20x − 28 = −4(5x + 7)
- Check by expanding the parentheses.
8.Factor fully: 15x2 + 5x + 35
Answer: 5(3x2+x+7)
- Highest common factor: 5
- 15x2 + 5x + 35 = 5(3x2 + x + 7)
- Check by expanding the parentheses.
9.Factor fully: 24ab + 28a
Answer: 4a(6b + 7)
- Highest common factor: 4a
- 24ab + 28a = 4a(6b + 7)
- Check by expanding the parentheses.
10.Factor fully: −45x − 81
Answer: −9(5x + 9)
- Highest common factor: −9
- −45x − 81 = −9(5x + 9)
- Check by expanding the parentheses.
11.Factor fully: 10x2 + 25x + 45
Answer: 5(2x2+5x+9)
- Highest common factor: 5
- 10x2 + 25x + 45 = 5(2x2 + 5x + 9)
- Check by expanding the parentheses.
12.Factor fully: 12ab − 3a
Answer: 3a(4b − 1)
- Highest common factor: 3a
- 12ab − 3a = 3a(4b − 1)
- Check by expanding the parentheses.
Marking tips
- Give credit for correct method even when the final answer slips — the working shows where the thinking went right.
- For open-ended tasks, use the success criteria as a checklist rather than looking for one "right" answer.
- Celebrate what went well first, then pick one thing to work on next.