9th Grade Factoring Expressions (Common Factors) Worksheet — Level 2 — Practice Set 3 — Answers
Answer sheet with worked solutions for the 9th Grade algebraic expressions worksheet.
9th Grade Factoring Expressions (Common Factors) Worksheet — Level 2 — Practice Set 3 — Answers
Find the highest common factor of the terms and write it outside the parentheses.
1.Factor fully: 20a − 8b
Answer: 4(5a − 2b)
- Highest common factor: 4
- 20a − 8b = 4(5a − 2b)
- Check by expanding the parentheses.
2.Factor fully: 6x2 − 6x
Answer: 6x(x − 1)
- Highest common factor: 6x
- 6x2 − 6x = 6x(x − 1)
- Check by expanding the parentheses.
3.Factor fully: 45a − 81b
Answer: 9(5a − 9b)
- Highest common factor: 9
- 45a − 81b = 9(5a − 9b)
- Check by expanding the parentheses.
4.Factor fully: 15x2 + 27x
Answer: 3x(5x + 9)
- Highest common factor: 3x
- 15x2 + 27x = 3x(5x + 9)
- Check by expanding the parentheses.
5.Factor fully: 42m + 7n
Answer: 7(6m + n)
- Highest common factor: 7
- 42m + 7n = 7(6m + n)
- Check by expanding the parentheses.
6.Factor fully: 20x2 − 45x
Answer: 5x(4x − 9)
- Highest common factor: 5x
- 20x2 − 45x = 5x(4x − 9)
- Check by expanding the parentheses.
7.Factor fully: 21m + 49n
Answer: 7(3m + 7n)
- Highest common factor: 7
- 21m + 49n = 7(3m + 7n)
- Check by expanding the parentheses.
8.Factor fully: 4x2 − 10x
Answer: 2x(2x − 5)
- Highest common factor: 2x
- 4x2 − 10x = 2x(2x − 5)
- Check by expanding the parentheses.
9.Factor fully: 9a − 63b
Answer: 9(a − 7b)
- Highest common factor: 9
- 9a − 63b = 9(a − 7b)
- Check by expanding the parentheses.
10.Factor fully: 9x2 − 15x
Answer: 3x(3x − 5)
- Highest common factor: 3x
- 9x2 − 15x = 3x(3x − 5)
- Check by expanding the parentheses.
11.Factor fully: 40x + 8y
Answer: 8(5x + y)
- Highest common factor: 8
- 40x + 8y = 8(5x + y)
- Check by expanding the parentheses.
12.Factor fully: 16x2 + 36x
Answer: 4x(4x + 9)
- Highest common factor: 4x
- 16x2 + 36x = 4x(4x + 9)
- 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.