Question

Express $\frac{-42}{98}$ as a rational number with denominator 7.

Answer 1

If $\frac{a}{b}$ is a rational number and $m$ is a common divisor of $a\mathrm{and}b$, then $\frac{a}{b}=\frac{a÷m}{b÷m}$.

∴ $\frac{-42}{98}=\frac{-42÷14}{98÷14}=\frac{-3}{7}$