Question

Multiply:

$17$ by $\frac{-21}{85}$

Answer 1

We know, $\mathrm{Product}\mathrm{of}\mathrm{two}\mathrm{rational}\mathrm{numbers}=\frac{\mathrm{Product}\mathrm{of}\mathrm{their}\mathrm{numerators}}{\mathrm{Product}\mathrm{of}\mathrm{their}\mathrm{denominators}}$

So, $17$ by $\frac{-21}{85}$

$$\begin{gathered} =\frac{17}{1}\times \frac{-21}{85} \\ =\frac{\cancel{17}\times (-21)}{1\times {\displaystyle \underset{5}{\cancel{85}}}} \\ =\frac{-21}{5} \end{gathered}$$

Hence, $17$ by $\frac{-21}{85}$ is $\frac{-21}{5}$.