4400 Higher November 2009 Paper 3 Q19
19
(a) Simplify \(\dfrac{x^2}{x^2 - 2x}\) (2)
(b) Simplify \(\dfrac{2}{2x - 1} - \dfrac{1}{x + 1}\) (4)
| Scheme | Marks |
|---|---|
| \(x^2/x(x - 2)\) | M1 |
| \(x/(x - 2)\) | A1 |
| (2) |
Notes
M1: M1 for \(x(x - 2)\)
A1: brackets not necessary
| Scheme | Marks |
|---|---|
| \(\dfrac{2(x + 1) - (2x - 1)}{(2x - 1)(x + 1)}\) | M2 |
| \(\dfrac{2x + 2 - 2x + 1}{(2x - 1)(x + 1)}\) | M1 |
| \(\dfrac{3}{(2x - 1)(x + 1)}\) oe | A1 |
| (4) | |
| (6 marks) |
Notes
M2: M1 for \((2x - 1)(x + 1)\) seen
A1: \(\dfrac{3}{2x^2 + x - 1}\)