Higher June 2017 Paper 5 Q17
17
(a) Simplify.\[\frac{x^2 - 16}{x^2 - 3x - 4}\]
[4]
(b) \((x + 3)(x - 4)(x + 5)\) is identical to \(x^3 + ax^2 - 17x + b\).
Find the value of \(a\) and the value of \(b\). [2]
| Answer | Marks | Part marks and guidance | |
|---|---|---|---|
| \(\dfrac{x + 4}{x + 1}\) final answer nfww | 4 | M1 for \((x + 4)(x - 4)\) AND M2 for \((x - 4)(x + 1)\) Or M1 for \(x(x + 1) - 4(x + 1)\) seen or \(x(x - 4) + 1(x - 4)\) seen or for \((x + a)(x + b)\) where \(a + b = -3\) or \(ab = -4\) | nfww please check working not just answer |
| Answer | Marks | Part marks and guidance | |
|---|---|---|---|
| 4 and −60 | 2 | B1 for each | For 2 marks or B1, accept answers embedded in expression provided no contradiction seen |