4400 Higher June 2008 Paper 3 Q14
14
(a) Factorise \(10y - 15\) (1)
(b) Factorise completely \(9p^2q + 12pq^2\) (2)
(c)
(i) Factorise \(x^2 + 6x - 16\)
(ii) Solve \(x^2 + 6x - 16 = 0\)
(3)| Scheme | Marks |
|---|---|
| \(5(2y - 3)\) | B1 |
| (1) |
Notes
B1: cao
| Scheme | Marks |
|---|---|
| \(3pq(3p + 4q)\) | B2 |
| (2) |
Notes
B2: B1 for \(3pq(...)\) or \(...(3p + 4q)\) or \(3p(3pq + 4q^2)\) or \(3q(3p^2 + 4pq)\) or \(pq(9p + 12q)\) or \(3(3p^2q + 4pq^2)\)
ie for two factors, one of which is \(3pq\) or \((3p + 4q)\), or for correct, but incomplete, factorisation
| Scheme | Marks |
|---|---|
| (i) Answer: \((x - 2)(x + 8)\) | B2 |
| (ii) Answer: 2, \(-8\) | B1 |
| (3) | |
| (6 marks) |
Notes
B2: B1 for one correct factor or \((x + 2)(x - 8)\)
B1: ft from (i) if two linear factors