Year 9 Factorising Expressions (Common Factors) Worksheet — Level 2 — Practice Set 2 — Answers
Answer sheet with worked solutions for the Year 9 algebraic expressions worksheet.
Year 9 Factorising Expressions (Common Factors) Worksheet — Level 2 — Practice Set 2 — Answers
Find the highest common factor of the terms and write it outside the brackets.
1.Factorise fully: 45m − 27n
Answer: 9(5m − 3n)
- Highest common factor: 9
- 45m − 27n = 9(5m − 3n)
- Check by expanding the brackets.
2.Factorise fully: 4x2 − 14x
Answer: 2x(2x − 7)
- Highest common factor: 2x
- 4x2 − 14x = 2x(2x − 7)
- Check by expanding the brackets.
3.Factorise fully: 9m − 3n
Answer: 3(3m − n)
- Highest common factor: 3
- 9m − 3n = 3(3m − n)
- Check by expanding the brackets.
4.Factorise fully: 5x2 + 4x
Answer: x(5x + 4)
- Highest common factor: x
- 5x2 + 4x = x(5x + 4)
- Check by expanding the brackets.
5.Factorise fully: 36x + 6y
Answer: 6(6x + y)
- Highest common factor: 6
- 36x + 6y = 6(6x + y)
- Check by expanding the brackets.
6.Factorise fully: 10x2 − 25x
Answer: 5x(2x − 5)
- Highest common factor: 5x
- 10x2 − 25x = 5x(2x − 5)
- Check by expanding the brackets.
7.Factorise fully: 25x − 45y
Answer: 5(5x − 9y)
- Highest common factor: 5
- 25x − 45y = 5(5x − 9y)
- Check by expanding the brackets.
8.Factorise fully: 15x2 + 10x
Answer: 5x(3x + 2)
- Highest common factor: 5x
- 15x2 + 10x = 5x(3x + 2)
- Check by expanding the brackets.
9.Factorise fully: 36a + 6b
Answer: 6(6a + b)
- Highest common factor: 6
- 36a + 6b = 6(6a + b)
- Check by expanding the brackets.
10.Factorise fully: 2x2 − x
Answer: x(2x − 1)
- Highest common factor: x
- 2x2 − x = x(2x − 1)
- Check by expanding the brackets.
11.Factorise fully: 35a − 56b
Answer: 7(5a − 8b)
- Highest common factor: 7
- 35a − 56b = 7(5a − 8b)
- Check by expanding the brackets.
12.Factorise fully: 25x2 + 30x
Answer: 5x(5x + 6)
- Highest common factor: 5x
- 25x2 + 30x = 5x(5x + 6)
- 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.