Year 9 Factorising Expressions (Common Factors) Worksheet — Level 2 — Answers
Answer sheet with worked solutions for the Year 9 algebraic expressions worksheet.
Year 9 Factorising Expressions (Common Factors) Worksheet — Level 2 — Answers
Find the highest common factor of the terms and write it outside the brackets.
1.Factorise fully: 8m + 4n
Answer: 4(2m + n)
- Highest common factor: 4
- 8m + 4n = 4(2m + n)
- Check by expanding the brackets.
2.Factorise fully: 4x2 − 28x
Answer: 4x(x − 7)
- Highest common factor: 4x
- 4x2 − 28x = 4x(x − 7)
- Check by expanding the brackets.
3.Factorise fully: 15m − 35n
Answer: 5(3m − 7n)
- Highest common factor: 5
- 15m − 35n = 5(3m − 7n)
- Check by expanding the brackets.
4.Factorise fully: 25x2 − 40x
Answer: 5x(5x − 8)
- Highest common factor: 5x
- 25x2 − 40x = 5x(5x − 8)
- Check by expanding the brackets.
5.Factorise fully: 12a + 20b
Answer: 4(3a + 5b)
- Highest common factor: 4
- 12a + 20b = 4(3a + 5b)
- Check by expanding the brackets.
6.Factorise fully: 12x2 − 27x
Answer: 3x(4x − 9)
- Highest common factor: 3x
- 12x2 − 27x = 3x(4x − 9)
- Check by expanding the brackets.
7.Factorise fully: 8m + 10n
Answer: 2(4m + 5n)
- Highest common factor: 2
- 8m + 10n = 2(4m + 5n)
- Check by expanding the brackets.
8.Factorise fully: 6x2 − 3x
Answer: 3x(2x − 1)
- Highest common factor: 3x
- 6x2 − 3x = 3x(2x − 1)
- Check by expanding the brackets.
9.Factorise fully: 6a − 12b
Answer: 6(a − 2b)
- Highest common factor: 6
- 6a − 12b = 6(a − 2b)
- Check by expanding the brackets.
10.Factorise fully: x2 − 4x
Answer: x(x − 4)
- Highest common factor: x
- x2 − 4x = x(x − 4)
- Check by expanding the brackets.
11.Factorise fully: 8a − 64b
Answer: 8(a − 8b)
- Highest common factor: 8
- 8a − 64b = 8(a − 8b)
- Check by expanding the brackets.
12.Factorise fully: 8x2 − 28x
Answer: 4x(2x − 7)
- Highest common factor: 4x
- 8x2 − 28x = 4x(2x − 7)
- Check by expanding the brackets.
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.