Year 9 Factorising Expressions (Common Factors) Worksheet — Level 1 — Practice Set 3 — Answers
Answer sheet with worked solutions for the Year 9 algebraic expressions worksheet.
Success TutoringWorksheetsAnswer sheetYear 9 · Mathematics · Algebraic ExpressionsYear 9 Factorising Expressions (Common Factors) Worksheet — Level 1 — Practice Set 3 — Answers
Find the highest common factor of the terms and write it outside the brackets.
1.Factorise fully: 5x − 20
Answer: 5(x − 4)
- Highest common factor: 5
- 5x − 20 = 5(x − 4)
- Check by expanding the brackets.
2.Factorise fully: 15x + 3
Answer: 3(5x + 1)
- Highest common factor: 3
- 15x + 3 = 3(5x + 1)
- Check by expanding the brackets.
3.Factorise fully: 10x + 4
Answer: 2(5x + 2)
- Highest common factor: 2
- 10x + 4 = 2(5x + 2)
- Check by expanding the brackets.
4.Factorise fully: 18x − 48
Answer: 6(3x − 8)
- Highest common factor: 6
- 18x − 48 = 6(3x − 8)
- Check by expanding the brackets.
5.Factorise fully: 32x + 72
Answer: 8(4x + 9)
- Highest common factor: 8
- 32x + 72 = 8(4x + 9)
- Check by expanding the brackets.
6.Factorise fully: 40x + 32
Answer: 8(5x + 4)
- Highest common factor: 8
- 40x + 32 = 8(5x + 4)
- Check by expanding the brackets.
7.Factorise fully: 16x − 40
Answer: 8(2x − 5)
- Highest common factor: 8
- 16x − 40 = 8(2x − 5)
- Check by expanding the brackets.
8.Factorise fully: 7x − 28
Answer: 7(x − 4)
- Highest common factor: 7
- 7x − 28 = 7(x − 4)
- Check by expanding the brackets.
9.Factorise fully: 9x + 3
Answer: 3(3x + 1)
- Highest common factor: 3
- 9x + 3 = 3(3x + 1)
- Check by expanding the brackets.
10.Factorise fully: 40x − 56
Answer: 8(5x − 7)
- Highest common factor: 8
- 40x − 56 = 8(5x − 7)
- Check by expanding the brackets.
11.Factorise fully: 4x − 32
Answer: 4(x − 8)
- Highest common factor: 4
- 4x − 32 = 4(x − 8)
- Check by expanding the brackets.
12.Factorise fully: 30x − 12
Answer: 6(5x − 2)
- Highest common factor: 6
- 30x − 12 = 6(5x − 2)
- 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.