Higher June 2019 Paper 1 Q12
12
Show clear algebraic working. (4)
| Scheme | Marks |
|---|---|
| \((2x - 3)(x - 2)\) | B2 |
| (2) |
Notes
B2: or \((3 - 2x)(2 - x)\)
(B1 for \((2x + a)(x + b)\) where \(ab = 6\) or \(2b + a = -7\) eg \((2x + 3)(x + 2)\), \((2x - 5)(x - 1)\)), etc or for
| Scheme | Marks |
|---|---|
| \(4m + 9 = 3(7 - 2m)\) | M1 |
| \(4m + 9 = 21 - 6m\) | M1 |
| \(4m + 6m = 21 - 9\) or \(10m = 12\) or \(-21 + 9 = -6m - 4m\) or \(-10m = -12\) | M1 |
Working required Answer: \(\dfrac{12}{10}\) oe | A1 |
| (4) |
Notes
M1: for removing fraction
M1: for correct expansion of bracket in a correct equation
M1: for a correct equation with \(m\) terms isolated on one side
ft their equation if first M1 awarded
A1: dep on at least M2
[SC: B2 for an answer of \(m = 2\) with working shown (from \(4m + 9 = 21 - 2m\) oe) or \(m = -0.2\) oe with working shown (from \(4m + 9 = 7 - 6m\) oe)]
| Scheme | Marks |
|---|---|
| \(\dfrac{4}{3}m + 3 = 7 - 2m\) | M1 |
| \(\dfrac{4}{3}m + 2m = 7 - 3\) oe | M1 |
| \(10m = 3 \times 4\) oe | M1 |
Working required Answer: \(\dfrac{12}{10}\) oe | A1 |
Notes
M1: Division of each term on LHS by 3
M1: for a correct equation with \(m\) terms isolated on one side
ft their equation if first M1 awarded
M1: For removing fraction in a fully correct equation
A1: dep on at least M2
| Scheme | Marks |
|---|---|
| \(\dfrac{y^{\frac{1}{4}}}{y}\) or \(\sqrt[4]{y} = y^{\frac{1}{4}}\) or \(y^{\frac{1}{4} - 1}\) | M1 |
| \(y^{-\frac{3}{4}}\) | A1 |
| (2) | |
| (8 marks) |
Notes
M1: or \(b = -\dfrac{3}{4}\)