Year 12 Factorising and Solving Quadratics Worksheet — Level 1 — Practice Set 3 — Answers
Answer sheet with worked solutions for the Year 12 quadratics worksheet.
Success TutoringWorksheetsAnswer sheetYear 12 · Mathematics · QuadraticsYear 12 Factorising and Solving Quadratics Worksheet — Level 1 — Practice Set 3 — Answers
Factorise each quadratic.
1.Factorise: x2 − 5x − 36
Answer: (x − 9)(x + 4)
- Find two numbers that multiply to −36 and add to −5: −9 and 4
2.Factorise: x2 + x − 6
Answer: (x + 3)(x − 2)
- Find two numbers that multiply to −6 and add to 1: 3 and −2
3.Factorise: x2 − 6x − 7
Answer: (x + 1)(x − 7)
- Find two numbers that multiply to −7 and add to −6: 1 and −7
4.Factorise: x2 + 3x − 28
Answer: (x + 7)(x − 4)
- Find two numbers that multiply to −28 and add to 3: 7 and −4
5.Factorise: x2 − 9x + 18
Answer: (x − 3)(x − 6)
- Find two numbers that multiply to 18 and add to −9: −3 and −6
6.Factorise: x2 − 10x + 24
Answer: (x − 4)(x − 6)
- Find two numbers that multiply to 24 and add to −10: −4 and −6
7.Factorise: x2 + 5x − 6
Answer: (x + 6)(x − 1)
- Find two numbers that multiply to −6 and add to 5: 6 and −1
8.Factorise: x2 + 9x + 20
Answer: (x + 5)(x + 4)
- Find two numbers that multiply to 20 and add to 9: 5 and 4
9.Factorise: x2 + 15x + 56
Answer: (x + 8)(x + 7)
- Find two numbers that multiply to 56 and add to 15: 8 and 7
10.Factorise: x2 − 6x − 16
Answer: (x + 2)(x − 8)
- Find two numbers that multiply to −16 and add to −6: 2 and −8
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.