Mock Set 1 Paper 02 Calculator

\begin{aligned} &2x + y = 3 \quad (1) \\ &5x + 3y = 7 \quad (2) \\ &\text{Multiply (1) by 3:} \quad 6x + 3y = 9 \quad (3) \\ &(3) - (2): \quad (6x - 5x) + (3y - 3y) = 9 - 7 \\ &x = 2 \\ &\text{Substitute into (1):} \quad 2(2) + y = 3 \\ &4 + y = 3 \quad \Rightarrow \quad y = -1 \end{aligned}