Question

The sum of two rational numbers is $\frac{-4}{5}$.If one of them is $\frac{-11}{20}$, find the other

Answer 1

$\because \frac{-11}{20}+$ a rational number$=\frac{-4}{5}$

$\therefore$ the required rational number$=\frac{-4}{5}-\left(\frac{-11}{20}\right)$

$=\frac{-4}{5}+\frac{11}{20}$

$=\frac{-4\times 4}{5\times 4}+\frac{11}{20}$

$=\frac{-16}{20}+\frac{11}{20}$

$=\frac{-16+11}{20}=\frac{-5}{20}=\frac{-1}{4}$

Thus, the other rational number $=\frac{-1}{4}$