Higher June 2022 Paper 4 Q14
14
\[(x + 2)(3x + a)(bx + 3) = 6x^3 + 11x^2 - 17x - 30\]Find the value of \(a\) and the value of \(b\). [2]
| Answer | Marks | Part marks and guidance | |
|---|---|---|---|
| [\(a =\)] −5 [\(b =\)] 2 | 2 | B1 for one correct or M1 for any pair of original brackets correctly expanded e.g. \(3x^2 + ax + 6x + 2a\) or \(1[x] \times 3[x] \times b[x] = 6[x^3]\) or \(2 \times a \times 3 = -30\) or better | allow seen in a table |