4. Выполните действия: а) \(\frac{6}{7}\cdot\frac{14}{15}\); б) \(2\frac{2}{5}:1\frac{1}{5}\).

1. \(\frac{6}{7}\cdot\frac{14}{15}=\frac{6\cdot14}{7\cdot15}=\frac{4}{5}\).
2. \(2\frac{2}{5}:1\frac{1}{5}=\frac{12}{5}:\frac{6}{5}=\frac{12}{5}\cdot\frac{5}{6}=2\).

Ответ: а) \(\frac{4}{5}\); б) 2.