4MA0 Higher June 2013 Paper 4R Q13
13
(a) Solve the simultaneous equations \[\begin{aligned} 5x + 3y &= 9 \\ 7x - 2y &= 25 \end{aligned}\] Show clear algebraic working. (4)
(b) \(P\) is the point of intersection of the lines with equations \(5x + 3y = 9\) and \(7x - 2y = 25\)
Write down the coordinates of \(P\). (1)
Write down the coordinates of \(P\). (1)
| Scheme | Marks |
|---|---|
| \(10x + 6y = 18\) \(21x - 6y = 75\) or \(35x + 21y = 63\) \(35x - 10y = 125\) | M1 |
| \(x = 3\) or \(y = -2\) | A1 |
| eg \(5 \times 3 + 3y = 9\) | M1 |
| 3 −2 | A1 |
| (4) |
Notes
M1: for coefficients of \(x\) or \(y\) the same or for correct rearrangement of one equation followed by substitution in the other eg \(5x + 3\left(\dfrac{7x - 25}{2}\right) = 9\)
M1: (dep on first M1) for substituting for the other variable
A1: cao dep Award full marks for correct values if at least first M1 scored
| Scheme | Marks |
|---|---|
| 3 −2 | B1 |
| (1) |
Notes
B1: ft from (a)