Higher November 2017 Paper 5 Q19
19 Solve these simultaneous equations algebraically.
\[\begin{aligned} y &= 2x^2 - 7x + 4 \\ y &= 4x - 1 \end{aligned}\][6]| Answer | Marks | Part marks and guidance | |
|---|---|---|---|
| \(x = \frac{1}{2}\) oe \(y = 1\) \(x = 5\) \(y = 19\) nfww | 6 | M1 for \(2x^2 - 7x + 4 = 4x - 1\) oe M1 for \(2x^2 - 11x + 5\) [ = 0] oe 3 term eqn | Implies previous M1 |
| M2 for \((2x - 1)(x - 5)\) [ = 0] or M1 for \((2x + a)(x + b)\) [ = 0] where \(ab = 5\) or \(2b + a = -11\) | FT their 3 term quadratic equation M2 for complete the square or for formula condone 1 error M1 for \(\left(x - \dfrac{11}{4}\right)^2\) oe or for correct formula used with 2 errors | ||
| A1 for \(x = \frac{1}{2}\) oe and \(x = 5\) | |||