Ответ:

\(\frac{6}{15}\cdot\frac{15}{30}=\frac{1}{5}\).

\(\frac{9}{15}\cdot\frac{10}{30}=\frac{1}{5}\).

Ответ: \(\frac{6}{15}\cdot\frac{15}{30}=\frac{9}{15}\cdot\frac{10}{30}\).