Higher June 2025 Paper 1 Q1
1 Solve the simultaneous equations
\[\begin{aligned} 2x + 5y &= 18 \\ 2x + y &= 6 \end{aligned}\][3 marks]
| Answer | Mark | Comments |
|---|---|---|
| Correct method to eliminate one variable | M1 | eg \(5y - y = 18 - 6\) or \(18 - 5y = 6 - y\) or \(5 \times 2x - 2x = 5 \times 6 - 18\) or \(\dfrac{18 - 2x}{5} = 6 - 2x\) |
| \(4y = 12\) or \(-4y = -12\) or \(y = 3\) or \(8x = 12\) or \(-8x = -12\) or \(x = 1.5\) | M1dep | oe equation in form \(ax = b\) or \(cy = d\) |
| \(x = 1.5\) and \(y = 3\) | A1 | oe |
Additional guidance
| Intention to subtract is sufficient for M1 eg \(\begin{aligned} 2x + 5y &= 18 \\ \underline{2x + \phantom{5}y} &\underline{{}= 6} \end{aligned}\ -\) | M1 |
| Correct values embedded in both equations | M2A0 |
| Correct values embedded in one equation | M1M0A0 |