Year 10 Factorising Expressions (Common Factors) Worksheet — Level 3 — Practice Set 4 — Answers
Answer sheet with worked solutions for the Year 10 algebraic expressions worksheet.
Year 10 Factorising Expressions (Common Factors) Worksheet — Level 3 — Practice Set 4 — Answers
Take out the highest common factor. Where the first term is negative, take out a negative factor.
1.Factorise fully: −40x + 48
Answer: −8(5x − 6)
- Highest common factor: −8
- −40x + 48 = −8(5x − 6)
- Check by expanding the brackets.
2.Factorise fully: 10x2 − 35x + 20
Answer: 5(2x2−7x+4)
- Highest common factor: 5
- 10x2 − 35x + 20 = 5(2x2 − 7x + 4)
- Check by expanding the brackets.
3.Factorise fully: 30ab − 35a
Answer: 5a(6b − 7)
- Highest common factor: 5a
- 30ab − 35a = 5a(6b − 7)
- Check by expanding the brackets.
4.Factorise fully: −18x + 27
Answer: −9(2x − 3)
- Highest common factor: −9
- −18x + 27 = −9(2x − 3)
- Check by expanding the brackets.
5.Factorise fully: 10x2 + 15x − 10
Answer: 5(2x2+3x−2)
- Highest common factor: 5
- 10x2 + 15x − 10 = 5(2x2 + 3x − 2)
- Check by expanding the brackets.
6.Factorise fully: 6ab − 10a
Answer: 2a(3b − 5)
- Highest common factor: 2a
- 6ab − 10a = 2a(3b − 5)
- Check by expanding the brackets.
7.Factorise fully: −30x + 18
Answer: −6(5x − 3)
- Highest common factor: −6
- −30x + 18 = −6(5x − 3)
- Check by expanding the brackets.
8.Factorise fully: 8x2 − 2x + 18
Answer: 2(4x2−x+9)
- Highest common factor: 2
- 8x2 − 2x + 18 = 2(4x2 − x + 9)
- Check by expanding the brackets.
9.Factorise fully: 5ab + 20a
Answer: 5a(b + 4)
- Highest common factor: 5a
- 5ab + 20a = 5a(b + 4)
- Check by expanding the brackets.
10.Factorise fully: −18x + 63
Answer: −9(2x − 7)
- Highest common factor: −9
- −18x + 63 = −9(2x − 7)
- Check by expanding the brackets.
11.Factorise fully: 15x2 + 15x − 25
Answer: 5(3x2+3x−5)
- Highest common factor: 5
- 15x2 + 15x − 25 = 5(3x2 + 3x − 5)
- Check by expanding the brackets.
12.Factorise fully: 3ab − 18a
Answer: 3a(b − 6)
- Highest common factor: 3a
- 3ab − 18a = 3a(b − 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.