Solve the following
Question:

Express $\frac{-48}{60}$ as a rational number with denominator $5 .$

Solution:

If $\frac{a}{b}$ is a rational integer and $m$ is a common divisor of $a$ and $b$, then $\frac{a}{b}=\frac{a \div m}{b \div m}$.

$\therefore \frac{-48}{60}=\frac{-48 \div 12}{60 \div 12}=\frac{-4}{5}$