5.487 Выполните действие: a) \(\frac{7}{15} \cdot 5\) b) \(\frac{5}{18} \cdot 12\) c) \(2 \cdot \frac{2}{9}\) d) \(\frac{14}{121} \cdot \frac{11}{28}\)

а) \(\frac{7}{15} \cdot 5 = \frac{7 \cdot 5}{15} = \frac{35}{15}\). Сократим на 5: \(\frac{35}{15} = \frac{7}{3}\) б) \(\frac{5}{18} \cdot 12 = \frac{5 \cdot 12}{18} = \frac{60}{18}\). Сократим на 6: \(\frac{60}{18} = \frac{10}{3}\) в) \(2 \cdot \frac{2}{9} = \frac{2 \cdot 2}{9} = \frac{4}{9}\) г) \(\frac{14}{121} \cdot \frac{11}{28} = \frac{14 \cdot 11}{121 \cdot 28} = \frac{154}{3388}\). Сократим на 154: \(\frac{154}{3388} = \frac{1}{22}\) Ответ: a) \(\frac{7}{3}\) b) \(\frac{10}{3}\) c) \(\frac{4}{9}\) d) \(\frac{1}{22}\)