8th Grade Factoring Expressions (Common Factors) Worksheet — Level 2 — Practice Set 2 — Answers
Answer sheet with worked solutions for the 8th Grade algebraic expressions worksheet.
8th Grade Factoring Expressions (Common Factors) Worksheet — Level 2 — Practice Set 2 — Answers
Find the highest common factor of the terms and write it outside the parentheses.
1.Factor fully: 15a + 35b
Answer: 5(3a + 7b)
- Highest common factor: 5
- 15a + 35b = 5(3a + 7b)
- Check by expanding the parentheses.
2.Factor fully: 4x2 + 9x
Answer: x(4x + 9)
- Highest common factor: x
- 4x2 + 9x = x(4x + 9)
- Check by expanding the parentheses.
3.Factor fully: 24x − 6y
Answer: 6(4x − y)
- Highest common factor: 6
- 24x − 6y = 6(4x − y)
- Check by expanding the parentheses.
4.Factor fully: 2x2 + 10x
Answer: 2x(x + 5)
- Highest common factor: 2x
- 2x2 + 10x = 2x(x + 5)
- Check by expanding the parentheses.
5.Factor fully: 35a + 49b
Answer: 7(5a + 7b)
- Highest common factor: 7
- 35a + 49b = 7(5a + 7b)
- Check by expanding the parentheses.
6.Factor fully: 3x2 − 5x
Answer: x(3x − 5)
- Highest common factor: x
- 3x2 − 5x = x(3x − 5)
- Check by expanding the parentheses.
7.Factor fully: 54x − 45y
Answer: 9(6x − 5y)
- Highest common factor: 9
- 54x − 45y = 9(6x − 5y)
- Check by expanding the parentheses.
8.Factor fully: 24x2 − 20x
Answer: 4x(6x − 5)
- Highest common factor: 4x
- 24x2 − 20x = 4x(6x − 5)
- Check by expanding the parentheses.
9.Factor fully: 3x + 18y
Answer: 3(x + 6y)
- Highest common factor: 3
- 3x + 18y = 3(x + 6y)
- Check by expanding the parentheses.
10.Factor fully: 15x2 − 18x
Answer: 3x(5x − 6)
- Highest common factor: 3x
- 15x2 − 18x = 3x(5x − 6)
- Check by expanding the parentheses.
11.Factor fully: 5m − 40n
Answer: 5(m − 8n)
- Highest common factor: 5
- 5m − 40n = 5(m − 8n)
- Check by expanding the parentheses.
12.Factor fully: 30x2 + 42x
Answer: 6x(5x + 7)
- Highest common factor: 6x
- 30x2 + 42x = 6x(5x + 7)
- 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.