Question

Divide the sum of $\frac{-13}{5}$ and $\frac{12}{7}$ by the product of $\frac{-31}{7}\mathrm{and}\frac{-1}{2}.$

Answer 1

$$\begin{gathered} (\frac{-13}{5}+\frac{12}{7})÷(\frac{-31}{7}\times \frac{-1}{2}) \\ =\frac{-13\times 7+12\times 5}{35}÷\frac{31}{14} \\ =\frac{-91+60}{35}÷\frac{31}{14} \\ =\frac{-31}{35}\times \frac{14}{31} \\ =\frac{-2}{5} \end{gathered}$$