4MA0 Higher January 2018 Paper 3R Q15
15 Solve
\[\begin{aligned} 3x - 4y &= 8 \\ 5x - 2y &= 11 \end{aligned}\]Show clear algebraic working.
(3)
| Scheme | Marks |
|---|---|
| eg \(3x - 4y = 8\) \(10x - 4y = 22\) \(7x = 14\) or eg \(15x - 20y = 40\) \(15x - 6y = 33\) \(-14y = 7\) | M1 |
| eg \(3 \times \text{‘}2\text{’} - 4y = 8\) \(3x - 4 \times \text{‘}{-0.5}\text{’} = 8\) | M1 |
| \(2, -\dfrac{1}{2}\) | A1 |
| (3) |
Notes
M1: for a complete method to eliminate one variable (condone one arithmetic error)
M1: (Dep on M1) for substituting the found variable or starting again to eliminate the other variable
A1: dep on M1
NB: candidates showing no correct algebraic working score 0 marks.