8th Grade Factoring Expressions (Common Factors) Worksheet — Level 2 — Practice Set 3 — Answers
Answer sheet with worked solutions for the 8th Grade algebraic expressions worksheet.
8th 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: 16m − 4n
Answer: 4(4m − n)
- Highest common factor: 4
- 16m − 4n = 4(4m − n)
- Check by expanding the parentheses.
2.Factor fully: 6x2 − 18x
Answer: 6x(x − 3)
- Highest common factor: 6x
- 6x2 − 18x = 6x(x − 3)
- Check by expanding the parentheses.
3.Factor fully: 15m − 21n
Answer: 3(5m − 7n)
- Highest common factor: 3
- 15m − 21n = 3(5m − 7n)
- Check by expanding the parentheses.
4.Factor fully: 16x2 + 12x
Answer: 4x(4x + 3)
- Highest common factor: 4x
- 16x2 + 12x = 4x(4x + 3)
- Check by expanding the parentheses.
5.Factor fully: 18a − 48b
Answer: 6(3a − 8b)
- Highest common factor: 6
- 18a − 48b = 6(3a − 8b)
- Check by expanding the parentheses.
6.Factor fully: 12x2 + 8x
Answer: 4x(3x + 2)
- Highest common factor: 4x
- 12x2 + 8x = 4x(3x + 2)
- Check by expanding the parentheses.
7.Factor fully: 27m − 36n
Answer: 9(3m − 4n)
- Highest common factor: 9
- 27m − 36n = 9(3m − 4n)
- Check by expanding the parentheses.
8.Factor fully: 10x2 − 4x
Answer: 2x(5x − 2)
- Highest common factor: 2x
- 10x2 − 4x = 2x(5x − 2)
- Check by expanding the parentheses.
9.Factor fully: 9m − 81n
Answer: 9(m − 9n)
- Highest common factor: 9
- 9m − 81n = 9(m − 9n)
- Check by expanding the parentheses.
10.Factor fully: 30x2 + 48x
Answer: 6x(5x + 8)
- Highest common factor: 6x
- 30x2 + 48x = 6x(5x + 8)
- Check by expanding the parentheses.
11.Factor fully: 42m + 49n
Answer: 7(6m + 7n)
- Highest common factor: 7
- 42m + 49n = 7(6m + 7n)
- Check by expanding the parentheses.
12.Factor fully: 10x2 − 15x
Answer: 5x(2x − 3)
- Highest common factor: 5x
- 10x2 − 15x = 5x(2x − 3)
- 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.