Higher January 2020 Paper 2R Q7
7 Solve the simultaneous equations
\[\begin{aligned} 3x + 5y &= 6 \\ 7x - 5y &= -11 \end{aligned}\]
Show clear algebraic working.
(3)
| Scheme | Marks |
|---|---|
| (adding) \(10x = -5\) or \(21x + 35y = 42\) and \(21x - 15y = -33\) then \(50y = 75\) | M1 |
| \(x = -0.5\) oe | A1 |
| Working required Answer: \(y = 1.5\) oe | A1 |
| (3) | |
| (3 marks) |
Notes
M1: Correct method to eliminate \(x\) or \(y\) Or making coefficients of \(x\) or \(y\) the same and correct operator has been applied to eliminate \(x\) or \(y\) (2 out of 3 terms correct implies a correct operator)
or correct algebraic substitution for \(x\) or \(y\) into other equation
A1: Both A marks dep on M1