Higher November 2017 Paper 4 Q13
13
(a) Solve.
\(x^2 - 6x + 15 = 3x - 5\) [4]
(b) Expand and simplify.
\((2x - 1)(x + 5)(3x - 2)\) [4]
| Answer | Marks | Part marks and guidance | |
|---|---|---|---|
| 4 5 | 4 | B2 for one correct solution OR B1 for \(x^2 - 9x + 20 = 0\) M2 for \((x - 4)(x - 5) = 0\) or use of the formula with at most one error or M1 for two factors which when expanded give two terms correctly or use of the formula with at most two errors if 0 scored SC1 for correctly factorising their quadratic expression | |
| Answer | Marks | Part marks and guidance | |
|---|---|---|---|
| \(6x^3 + 23x^2 - 33x + 10\) | 4 | M3 for a fully correct method with at most one error e.g. \((2x^2 + 9x - 5)(3x - 2) = 6x^3 + 27x^2 - 15x - 4x^2 - 18x + 10\) or better or M2 for a correct method to multiply two brackets e.g. \(2x^2 + 10x - x - 5\) or \(3x^2 + 15x - 2x - 10\) or better or M1 for a correct method with at most two errors or a correct method to multiply two brackets with at most one error | |