Higher June 2024 Paper 1 Q14
14 Expand and simplify \((3x - 1)(2x + 3)(x - 5)\) (3)
| Answer | Mark | Mark scheme |
|---|---|---|
| \(6x^3 - 23x^2\) \(- 38x + 15\) | M1 | for method to find the product of any two linear expressions (3 out of 4 terms correct or 4 correct terms ignoring signs) eg \(6x^2 + 9x - 2x - 3\) or \(3x^2 - 15x - x + 5\) or \(2x^2 - 10x + 3x - 15\) |
| M1 | for a complete method to obtain all terms, half of which are correct (ft their first product) eg \(6x^3 + 7x^2 - 30x^2 - 35x - 3x + 15\) or \(6x^3 + 9x^2 - 32x^2 - 48x + 10x + 15\) or \(6x^3 - 2x^2 - 21x^2 - 45x + 7x + 15\) | |
| A1 | cao |
Additional guidance
Note that, for example, \(7x - 3\) in expansion of \((3x - 1)(2x + 3)\) is regarded as 3 correct terms
Do not award this mark for
eg \(6x^2 + 9x - 2x - 3 + 3x^2 - 15x - x + 5\)
First product must be quadratic with at least 3 terms but need not be simplified or may be simplified incorrectly