4MA0 Higher June 2015 Paper 3R Q14
14 Solve the simultaneous equations
\[\begin{aligned} 8x - 4y &= 7 \\ 12x - 8y &= 6 \end{aligned}\]Show clear algebraic working.
(3)
| Scheme | Marks |
|---|---|
| \(16x - 8y = 14\) \(12x - 8y = 6\) \(4x = 8\) | M1 |
| M1(dep) | |
| \(x = 2\) \(y = 2.25\) oe | A1 |
| (3) |
Notes
M1: for appropriate multiplication to get coefficients of \(x\) or \(y\) the same (condone one arithmetic error) with the correct operation to eliminate one variable or for correct rearrangement of one equation followed by substitution in the other (condone one arithmetic error).
M1(dep): to find value of second variable ft from value of their first variable
A1: Award 3 marks for correct values if at least first M1 scored