x + 0.4y = 3...(i) y = \(\frac{1}{2}\)x x = 2y x - 2y = 0....(ii) solve simultaneously; x + 0.4y = 3 - x - 2y = 0 2.4 = 3 y = \(\frac{3 \times 10}{2.4 \times 10} \) = \(\frac{30}{24} = \frac{5}{4}\) x - 2(\(\frac{5}{4}\)) = 0 x - \(\frac{5}{2}\) = 0 x = \(\frac{5}{2}\) x + y = \(\frac{5}{2} + \frac{5}{4}\) \(\frac{10 + 5}{4} = \frac{15}{4}\) = 3\(\frac{3}{4}\)