Specimen 2020 Paper 2 Q16
16 Simplify \(\quad \dfrac{8x^3 - 50x}{2x(6x^2 - x - 35)}\)
Give your answer in the form \(\quad \dfrac{ax + b}{cx + d} \quad\) where \(a\), \(b\), \(c\) and \(d\) are integers. [5 marks]
| Answer | Mark | Comments |
|---|---|---|
| (numerator =) \(2x(4x^2 - 25)\) or \(\dfrac{4x^2 - 25}{6x^2 - x - 35}\) | B1 | |
| (numerator =) \(2x(2x + 5)(2x - 5)\) or \(\dfrac{(2x + 5)(2x - 5)}{6x^2 - x - 35}\) | B1 | |
| \((ax + b)(cx + d)\) where \(ac = 6\) and \(bd = \pm 35\) | M1 | |
| \((3x + 7)(2x - 5)\) | A1 | |
| \(\dfrac{2x + 5}{3x + 7}\) | A1 |