Foundation June 2017 Paper 2 Q24
24 Solve \(x^2 + 5x - 24 = 0\) (3)
| Answer | Mark | Notes |
|---|---|---|
| \(x = -8\), \(x = 3\) | M1 | for factorisation or for substitution into quadratic formula \((x \pm a)(x \pm b)\) where product of \(a\) and \(b = 24\), eg \((x \pm 4)(x \pm 6)\) or difference of \(a\) and \(b = 5\), eg \((x \pm 2)(x \pm 7)\) \(\dfrac{-5 \pm \sqrt{5^2 - 4 \times 1 \times {-24}}}{2}\) oe (condone one sign error) |
| M1 | for \((x + 8)(x - 3)\) or for \(\dfrac{-5 \pm \sqrt{121}}{2}\) oe | |
| A1 | cao |