Higher June 2023 Paper 1R Q7
7
(a) Expand \(\;4x(x - 5)\) (1)
(b) Factorise \(\;y^2 - 9y + 20\) (2)
| Scheme | Marks |
|---|---|
| \(4x^2 - 20x\) | B1 |
| (1) |
Notes
B1: or \(-20x + 4x^2\)
| Scheme | Marks |
|---|---|
| \((y \pm 5)(y \pm 4)\) or \((5 \pm y)(4 \pm y)\) or \(y(y - 4) - 5(y - 4)\) or \(y(y - 5) - 4(y - 5)\) | M1 |
| Correct answer scores full marks (unless from obvious incorrect working) Answer: \((y - 5)(y - 4)\) | A1 |
| (2) | |
| (3 marks) |
Notes
M1: for \((y \pm 5)(y \pm 4)\)
or
\((5 \pm y)(4 \pm y)\)
or
for \((y + a)(y + b)\) where \(ab = 20\) or \(a + b = -9\)
A1: oe Allow any letter for \(y\)
Accept \((5 - y)(4 - y)\)