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: 3m + 3n
Answer: 3(m + n)
- Highest common factor: 3
- 3m + 3n = 3(m + n)
- Check by expanding the brackets.
2.Factorise fully: 6x2 − 2x
Answer: 2x(3x − 1)
- Highest common factor: 2x
- 6x2 − 2x = 2x(3x − 1)
- Check by expanding the brackets.
3.Factorise fully: 8m + 18n
Answer: 2(4m + 9n)
- Highest common factor: 2
- 8m + 18n = 2(4m + 9n)
- 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: 9m + 54n
Answer: 9(m + 6n)
- Highest common factor: 9
- 9m + 54n = 9(m + 6n)
- Check by expanding the brackets.
6.Factorise fully: 24x2 + 20x
Answer: 4x(6x + 5)
- Highest common factor: 4x
- 24x2 + 20x = 4x(6x + 5)
- Check by expanding the brackets.
7.Factorise fully: 24a + 16b
Answer: 8(3a + 2b)
- Highest common factor: 8
- 24a + 16b = 8(3a + 2b)
- Check by expanding the brackets.
8.Factorise fully: 6x2 − 5x
Answer: x(6x − 5)
- Highest common factor: x
- 6x2 − 5x = x(6x − 5)
- Check by expanding the brackets.
9.Factorise fully: 12a + 6b
Answer: 6(2a + b)
- Highest common factor: 6
- 12a + 6b = 6(2a + b)
- Check by expanding the brackets.
10.Factorise fully: 12x2 − 9x
Answer: 3x(4x − 3)
- Highest common factor: 3x
- 12x2 − 9x = 3x(4x − 3)
- Check by expanding the brackets.
11.Factorise fully: 30x + 48y
Answer: 6(5x + 8y)
- Highest common factor: 6
- 30x + 48y = 6(5x + 8y)
- Check by expanding the brackets.
12.Factorise fully: 36x2 − 6x
Answer: 6x(6x − 1)
- Highest common factor: 6x
- 36x2 − 6x = 6x(6x − 1)
- 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.