4MA0 Higher January 2016 Paper 4R Q12
12 Simplify fully \((2x + 3)^2 - (2x - 3)^2\)
(3)
| Scheme | Marks |
|---|---|
| \((4x^2 + 6x + 6x + 9) - (4x^2 - 6x - 6x + 9)\) | M1 |
| \(4x^2 + 6x + 6x + 9 - 4x^2 + 6x + 6x - 9\) | M1 |
| \(24x\) | A1 |
| (3) |
Notes
M1: any one correct expansion
M1 for \(((2x + 3) + (2x - 3))((2x + 3) - (2x - 3))\)
M1: for dealing correctly with the negative sign
M1 for \((2x + 3 + 2x - 3)(2x + 3 - 2x + 3)\)