4400 Higher June 2009 Paper 3 Q18
18 Simplify fully \(\dfrac{5x^2 + 14x - 3}{50x^2 - 2}\)
(4)
| Scheme | Marks |
|---|---|
\(\dfrac{(5x - 1)(x + 3)}{2(25x^2 - 1)}\) \(\dfrac{(5x - 1)(x + 3)}{2(5x + 1)(5x - 1)}\) | B1 B1 B1 |
| \(\dfrac{x + 3}{2(5x + 1)}\) or \(\dfrac{x + 3}{10x + 2}\) | B1 |
| (4) | |
| (4 marks) |
Notes
B1 B1 B1: B1 for factorising numerator as \((5x - 1)(x + 3)\)
B1 for factorising denominator as \(2(25x^2 - 1)\)
B1 for factorising \(25x^2 - 1\) as \((5x + 1)(5x - 1)\)
or B2 for factorising denominator as \((5x - 1)(10x + 2)\) or \((5x + 1)(10x - 2)\)