5.486 Найдите произведение: a) \(\frac{8}{9} \cdot \frac{3}{4}\), б) \(\frac{11}{45} \cdot \frac{9}{22}\), в) \(\frac{51}{29} \cdot \frac{58}{85}\), г) \(\frac{1}{4} \cdot \frac{4}{5} \cdot \frac{5}{6}\).

a) \(\frac{8}{9} \cdot \frac{3}{4}\) = \(\frac{8 \cdot 3}{9 \cdot 4}\) = \(\frac{2 \cdot 1}{3 \cdot 1}\) = \(\frac{2}{3}\)

б) \(\frac{11}{45} \cdot \frac{9}{22}\) = \(\frac{11 \cdot 9}{45 \cdot 22}\) = \(\frac{1 \cdot 1}{5 \cdot 2}\) = \(\frac{1}{10}\)

в) \(\frac{51}{29} \cdot \frac{58}{85}\) = \(\frac{51 \cdot 58}{29 \cdot 85}\) = \(\frac{3 \cdot 2}{1 \cdot 5}\) = \(\frac{6}{5}\) = 1\(\frac{1}{5}\)

г) \(\frac{1}{4} \cdot \frac{4}{5} \cdot \frac{5}{6}\) = \(\frac{1 \cdot 4 \cdot 5}{4 \cdot 5 \cdot 6}\) = \(\frac{1 \cdot 1 \cdot 1}{1 \cdot 1 \cdot 6}\) = \(\frac{1}{6}\)

Ответ: a) \(\frac{2}{3}\), б) \(\frac{1}{10}\), в) 1\(\frac{1}{5}\), г) \(\frac{1}{6}\)