Вопрос:

1. Выполните действия, предварительно сократив дроби: а) \(\frac{14}{25}\cdot\frac{15}{21}\); б) \(3\frac{2}{8}:1\frac{11}{16}\); в) \(\left(\frac{5}{6}:\frac{9}{10}\right):\left(\frac{3}{4}-\frac{1}{6}\right)\).

Ответ:

а) \(\frac{14}{25}\cdot\frac{15}{21}=\frac{2}{5}\).

б) \(3\frac{2}{8}=\frac{13}{4}\), \(1\frac{11}{16}=\frac{27}{16}\).

\(\frac{13}{4}:\frac{27}{16}=\frac{13}{4}\cdot\frac{16}{27}=\frac{52}{27}=1\frac{25}{27}\).

в) \(\frac{5}{6}:\frac{9}{10}=\frac{5}{6}\cdot\frac{10}{9}=\frac{25}{27}\).

\(\frac{3}{4}-\frac{1}{6}=\frac{9}{12}-\frac{2}{12}=\frac{7}{12}\).

\(\frac{25}{27}:\frac{7}{12}=\frac{25}{27}\cdot\frac{12}{7}=\frac{100}{63}=1\frac{37}{63}\).

Ответ: а) \(\frac{2}{5}\); б) \(1\frac{25}{27}\); в) \(1\frac{37}{63}\).