[tex](x.y)ip(2.3) \\ x \times 2 = y \times 3 = k \\ x = \frac{k}{2} \\ y = \frac{k}{3} \\ a) \frac{ \frac{k}{2} + \frac{k}{3} }{ \frac{k}{2} } = \frac{ \frac{5k}{6} }{ \frac{k}{2} } = \frac{ \frac{5k}{6} }{2k} = \frac{5}{12} \\ b) \frac{ 4 \times \frac{k}{2} - \frac{k}{3} }{ \frac{k}{3} } = \frac{2k + \frac{k}{3} }{ \frac{k}{2} } = \frac{ \frac{7k}{3} }{ \frac{k}{2} } = \frac{7}{6} [/tex]
