Year 9 Factorising and Solving Quadratics Worksheet — Level 3 — Practice Set 4 — Answers
Answer sheet with worked solutions for the Year 9 quadratics worksheet.
Success TutoringWorksheetsAnswer sheetYear 9 · Mathematics · QuadraticsYear 9 Factorising and Solving Quadratics Worksheet — Level 3 — Practice Set 4 — Answers
Factorise, then use the null factor law.
1.Solve: 2x2 + 20x + 42 = 0
Answer: x = -3 or x = −7
- Factorise: (2x + 6)(x + 7) = 0
- 2x + 6 = 0 gives x = -3
- x + 7 = 0 gives x = −7
2.Solve: 2x2 + 3x − 20 = 0
Answer: x = or x = −4
- Factorise: (2x − 5)(x + 4) = 0
- 2x − 5 = 0 gives x =
- x + 4 = 0 gives x = −4
3.Solve: 2x2 + 8x − 24 = 0
Answer: x = 2 or x = −6
- Factorise: (2x − 4)(x + 6) = 0
- 2x − 4 = 0 gives x = 2
- x + 6 = 0 gives x = −6
4.Solve: 2x2 + 15x + 25 = 0
Answer: x = − or x = −5
- Factorise: (2x + 5)(x + 5) = 0
- 2x + 5 = 0 gives x = −
- x + 5 = 0 gives x = −5
5.Solve: 2x2 + 2x − 12 = 0
Answer: x = -3 or x = 2
- Factorise: (2x + 6)(x − 2) = 0
- 2x + 6 = 0 gives x = -3
- x − 2 = 0 gives x = 2
6.Solve: 3x2 − 10x − 8 = 0
Answer: x = − or x = 4
- Factorise: (3x + 2)(x − 4) = 0
- 3x + 2 = 0 gives x = −
- x − 4 = 0 gives x = 4
7.Solve: 3x2 + 33x + 54 = 0
Answer: x = -2 or x = −9
- Factorise: (3x + 6)(x + 9) = 0
- 3x + 6 = 0 gives x = -2
- x + 9 = 0 gives x = −9
8.Solve: 2x2 + 11x + 14 = 0
Answer: x = − or x = −2
- Factorise: (2x + 7)(x + 2) = 0
- 2x + 7 = 0 gives x = −
- x + 2 = 0 gives x = −2
9.Solve: 3x2 − 33x + 72 = 0
Answer: x = 3 or x = 8
- Factorise: (3x − 9)(x − 8) = 0
- 3x − 9 = 0 gives x = 3
- x − 8 = 0 gives x = 8
10.Solve: 2x2 + 7x + 3 = 0
Answer: x = − or x = −3
- Factorise: (2x + 1)(x + 3) = 0
- 2x + 1 = 0 gives x = −
- x + 3 = 0 gives x = −3
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