\[ \begin{align*} \dfrac{6}{13} \times \dfrac{5}{9} &= \dfrac{6\times 5}{13\times 9} \\ &= \dfrac{30}{117} \\ &= \dfrac{10}{39} \end{align*} \] \[ \begin{align*} \dfrac{4}{15} \times \dfrac{7}{8} &= \dfrac{4\times 7}{15\times 8} \\ &= \dfrac{28}{120} \\ &= \dfrac{7}{30} \end{align*} \] \[ \begin{align*} \dfrac{9}{14} \times \dfrac{2}{5} &= \dfrac{9\times 2}{14\times 5} \\ &= \dfrac{18}{70} \\ &= \dfrac{9}{35} \end{align*} \] \[ \begin{align*} 5 \times \dfrac{7}{18} &= \dfrac{5\times 7}{1\times 18} \\ &= \dfrac{35}{18} \end{align*} \]