Вопрос:

Вычислите: 5/13*7/8-2/5:2 3/5.

Ответ:

\[\frac{5}{13} \cdot \frac{7}{8} - \frac{2}{5}\ :2\frac{3}{5} = \frac{5}{13} \cdot \frac{7}{8} - \frac{2}{5}\ :\frac{13}{5} =\]

\[= \frac{5}{13} \cdot \frac{7}{8} - \frac{2}{5} \cdot \frac{5}{13} =\]

\[= \frac{5}{13} \cdot \left( \frac{7^{\backslash 5}}{8} - \frac{2^{\backslash 8}}{5} \right) =\]

\[= \frac{5}{13} \cdot \frac{35 - 16}{40} = \frac{5}{13} \cdot \frac{19}{40} =\]

\[= \frac{19}{13 \cdot 8} = \frac{19}{104}.\]