Higher June 2021 Paper 2 Q9
9
(i) Factorise \(x^2 + 2x - 24\) (2)
(ii) Hence solve \(x^2 + 2x - 24 = 0\) (1)
| Scheme | Marks |
|---|---|
| \((x \pm 6)(x \pm 4)\) | M1 |
| Working not required, so correct answer scores full marks Answer: \((x + 6)(x - 4)\) | A1 |
| (2) |
Notes
M1: or \((x + a)(x + b)\) where \(ab = -24\) or \(a + b = 2\)
| Scheme | Marks |
|---|---|
| Answer must come from the factors in (i) as the questions says ‘Hence solve…’ Answer: −6, 4 | B1ft |
| (1) | |
| (3 marks) |
Notes
B1ft: Must follow through from their factors in (i), so even if the answers 4 and −6 are given the mark can only be awarded if it follows from the factorisation in (i) (dep on 2 factors)
NB: Some students may show the whole of their working in the space for (i) or (ii). Please award the marks for (i) and (ii) so long as there is no ambiguity.