Question:
Express $\frac{-3}{5}$ as a rational number with denominator
(i) 20
(ii) −30
(iii) 35
(iv) −40
Solution:
If $\frac{a}{b}$ is a fraction and $m$ is a non-zero integer, then $\frac{a}{b}=\frac{a \times m}{b \times m}$.
Now,
(i) $\frac{-3}{5}=\frac{-3 \times 4}{5 \times 4}=\frac{-12}{20}$
(ii) $\frac{-3}{5}=\frac{-3 \times-6}{5 \times-6}=\frac{18}{-30}$
(iii) $\frac{-3}{5}=\frac{-3 \times 7}{5 \times 7}=\frac{-21}{35}$
(iv) $\frac{-3}{5}=\frac{-3 \times-8}{5 \times-8}=\frac{24}{-40}$