Year 9 Factorising Expressions (Common Factors) Worksheet — Level 2 — Practice Set 4 — Answers
Answer sheet with worked solutions for the Year 9 algebraic expressions worksheet.
Year 9 Factorising Expressions (Common Factors) Worksheet — Level 2 — Practice Set 4 — Answers
Find the highest common factor of the terms and write it outside the brackets.
1.Factorise fully: 6m − 2n
Answer: 2(3m − n)
- Highest common factor: 2
- 6m − 2n = 2(3m − n)
- Check by expanding the brackets.
2.Factorise fully: 2x2 + x
Answer: x(2x + 1)
- Highest common factor: x
- 2x2 + x = x(2x + 1)
- Check by expanding the brackets.
3.Factorise fully: 6a − 3b
Answer: 3(2a − b)
- Highest common factor: 3
- 6a − 3b = 3(2a − b)
- Check by expanding the brackets.
4.Factorise fully: 15x2 + 40x
Answer: 5x(3x + 8)
- Highest common factor: 5x
- 15x2 + 40x = 5x(3x + 8)
- Check by expanding the brackets.
5.Factorise fully: 4m − 18n
Answer: 2(2m − 9n)
- Highest common factor: 2
- 4m − 18n = 2(2m − 9n)
- Check by expanding the brackets.
6.Factorise fully: 10x2 + 12x
Answer: 2x(5x + 6)
- Highest common factor: 2x
- 10x2 + 12x = 2x(5x + 6)
- Check by expanding the brackets.
7.Factorise fully: 6x − 15y
Answer: 3(2x − 5y)
- Highest common factor: 3
- 6x − 15y = 3(2x − 5y)
- Check by expanding the brackets.
8.Factorise fully: 25x2 − 10x
Answer: 5x(5x − 2)
- Highest common factor: 5x
- 25x2 − 10x = 5x(5x − 2)
- Check by expanding the brackets.
9.Factorise fully: 28a − 63b
Answer: 7(4a − 9b)
- Highest common factor: 7
- 28a − 63b = 7(4a − 9b)
- Check by expanding the brackets.
10.Factorise fully: 20x2 + 35x
Answer: 5x(4x + 7)
- Highest common factor: 5x
- 20x2 + 35x = 5x(4x + 7)
- Check by expanding the brackets.
11.Factorise fully: 12x − 27y
Answer: 3(4x − 9y)
- Highest common factor: 3
- 12x − 27y = 3(4x − 9y)
- Check by expanding the brackets.
12.Factorise fully: 2x2 + 5x
Answer: x(2x + 5)
- Highest common factor: x
- 2x2 + 5x = x(2x + 5)
- 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.