4MA0 Higher June 2011 Paper 4 Q15
15
(a) Simplify \(\dfrac{8(x - 3)^2}{4(x - 3)}\) (2)
(b) Factorise \(a^2 - 144\) (2)
(c) Make \(q\) the subject of the formula \(p = \sqrt{q} - 5r\) (2)
(d) Solve \(\dfrac{4}{y - 4} = 5\) (3)
| Scheme | Marks |
|---|---|
| Correct cancelling 8 & 4 or brackets | M1 |
| \(2(x - 3)\) oe | A1 |
| (2) |
Notes
Apart from questions 5b, 8, 15d, 20b, 21b, 23, 24b (where the mark scheme states otherwise) the correct answer, unless clearly obtained by an incorrect method, should be taken to imply correct working.
| Scheme | Marks |
|---|---|
| \((a + 12)(a - 12)\) | B2 |
| (2) |
Notes
B2: B1 for \((a \pm 12)(a \pm 12)\)
| Scheme | Marks |
|---|---|
| \(p + 5r\) (\(=\sqrt{q}\)) | M1 |
| \((p + 5r)^2\) oe | A1 |
| (2) |
Notes
A1: do not isw (e.g. proceed onto \(p^2 + 25r^2\))
| Scheme | Marks |
|---|---|
| \(4 = 5(y - 4)\) oe | M1 |
| \(4 + (5 \times 4) = 5y\) Answer: must be 5 × 4 or 20 or LHS = 24 | M1 |
| 4.8 oe | A1 |
| (3) | |
| (Total 9 marks) |
Notes
M1: or \((y - 4)/4 = 1/5\)
M1: \(4/5 = y - 4\)
A1: dep on M2 correct answer only = M0M0A0