Вопрос:

№ 3. Вычислите: 1) \(2\frac{4}{5}-\left(2-1\frac{1}{15}\right):\frac{4}{9}\); 2) \((-10,6+13,42):4\); 3) \(-\frac{7}{7}\cdot(59-73)\).

Ответ:

  1. \(2\frac{4}{5}=\frac{14}{5}\), а \(1\frac{1}{15}=\frac{16}{15}\).

    \[2-\frac{16}{15}=\frac{14}{15}\]

    \[\frac{14}{15}:\frac{4}{9}=\frac{14}{15}\cdot\frac{9}{4}=\frac{21}{10}\]

    \[\frac{14}{5}-\frac{21}{10}=\frac{28}{10}-\frac{21}{10}=\frac{7}{10}\]

  2. \[-10,6+13,42=2,82\]

    \[2,82:4=0,705\]

  3. \[-\frac{7}{7}\cdot(59-73)=-1\cdot(-14)=14\]

Ответ: 1) \(\frac{7}{10}\); 2) \(0,705\); 3) \(14\).