June 2024 Paper 1 Q8
8 Solve by factorising \(\quad 2x^3 - 9x^2 - 5x = 0\) [3 marks]
| Answer | Mark | Comments |
|---|---|---|
| \(x(2x^2 - 9x - 5)\) or \((2x^2 + x)(x - 5)\) or \((2x + 1)(x^2 - 5x)\) or states \(x = 0\) and \((2x^2 - 9x - 5)\) | M1 | |
| \(x(2x + 1)(x - 5)\) or states \(x = 0\) and \((2x + 1)(x - 5)\) | M1dep | do not accept \(x(2x + 1)(2x - 10)\) unless recovered by correct solutions |
| \((x =)\ 0,\ 5,\ -0.5\) | A1 | oe but must come from factorising in M1dep |
Additional guidance
| \((2x + 1)(x - 5)\) if no other marks scored | SC1 |
| \((x =)\ 0,\ 5,\ -0.5\) without working or by using factor theorem to find solutions without writing it as a product of factors or by using quadratic formula (must be all 3 correct answers) | SC1 |