Вопрос:

1. \((1\frac{3}{5}+2\frac{1}{5}):1,9\times(1,7-\frac{4}{5}):\frac{3}{7}\).

Ответ:

Вычислим по порядку:

\(1\frac{3}{5}+2\frac{1}{5}=3\frac{4}{5}=\frac{19}{5}\).

\(1,7-\frac{4}{5}=\frac{17}{10}-\frac{8}{10}=\frac{9}{10}\).

\(\frac{19}{5}:1,9\times\frac{9}{10}:\frac{3}{7}=\frac{19}{5}:\frac{19}{10}\times\frac{9}{10}:\frac{3}{7}\).

\(=2\times\frac{9}{10}\times\frac{7}{3}=\frac{21}{5}=4\frac{1}{5}\).

Ответ: \(4\frac{1}{5}\).