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 + 6x − 20 = 0
Answer: x = 2 or x = −5
- Factorise: (2x − 4)(x + 5) = 0
- 2x − 4 = 0 gives x = 2
- x + 5 = 0 gives x = −5
2.Solve: 3x2 + 12x + 9 = 0
Answer: x = -1 or x = −3
- Factorise: (3x + 3)(x + 3) = 0
- 3x + 3 = 0 gives x = -1
- x + 3 = 0 gives x = −3
3.Solve: 2x2 − x − 45 = 0
Answer: x = − or x = 5
- Factorise: (2x + 9)(x − 5) = 0
- 2x + 9 = 0 gives x = −
- x − 5 = 0 gives x = 5
4.Solve: 2x2 − 15x − 8 = 0
Answer: x = − or x = 8
- Factorise: (2x + 1)(x − 8) = 0
- 2x + 1 = 0 gives x = −
- x − 8 = 0 gives x = 8
5.Solve: 2x2 + 8x − 64 = 0
Answer: x = 4 or x = −8
- Factorise: (2x − 8)(x + 8) = 0
- 2x − 8 = 0 gives x = 4
- x + 8 = 0 gives x = −8
6.Solve: 2x2 + 22x + 56 = 0
Answer: x = -4 or x = −7
- Factorise: (2x + 8)(x + 7) = 0
- 2x + 8 = 0 gives x = -4
- x + 7 = 0 gives x = −7
7.Solve: 2x2 + 4x − 16 = 0
Answer: x = 2 or x = −4
- Factorise: (2x − 4)(x + 4) = 0
- 2x − 4 = 0 gives x = 2
- x + 4 = 0 gives x = −4
8.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
9.Solve: 3x2 + 17x − 28 = 0
Answer: x = or x = −7
- Factorise: (3x − 4)(x + 7) = 0
- 3x − 4 = 0 gives x =
- x + 7 = 0 gives x = −7
10.Solve: 2x2 + 7x − 15 = 0
Answer: x = or x = −5
- Factorise: (2x − 3)(x + 5) = 0
- 2x − 3 = 0 gives x =
- x + 5 = 0 gives x = −5
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