Higher November 2023 Paper 2 Q9
9 Expand and simplify \((x + 7)(x - 2)(x + 3)\) (3)
| Answer | Mark | Mark scheme |
|---|---|---|
| \(x^3 + 8x^2 + x - 42\) | M1 | for a method to find the product of two linear expression (3 out of 4 terms correct or 4 correct terms ignoring signs), eg \(x^2 - 2x + 7x - 14\) or \(x^2 + 3x - 2x - 6\) or \(x^2 + 3x + 7x + 21\) |
| M1 | for a complete method to obtain all terms, half of which are correct (ft their first product), eg \(x^3 + 3x^2 - 2x^2 + 7x^2 - 6x + 21x - 14x - 42\) | |
| A1 | cao |
Additional guidance
Note that (eg) \(5x - 14\) in expansion of \((x + 7)(x - 2)\) is to be regarded as 3 correct terms.
First product must be quadratic with at least 3 terms but need not be simplified or may be simplified incorrectly