Реши уравнение a:1 5/7=2 2/5:2 2/35.

\[a\ :1\frac{5}{7} = 2\frac{2}{5}\ :2\frac{2}{35}\]

\[a\ :\frac{12}{7} = \frac{12}{5}\ :\frac{72}{35}\]

\[a\ :\frac{12}{7} = \frac{12}{5} \cdot \frac{35}{72}\]

\[a\ :\frac{12}{7} = \frac{12 \cdot 5 \cdot 7}{5 \cdot 12 \cdot 6}\]

\[a = \frac{7}{6} \cdot \frac{12}{7} = \frac{12}{6}\]

\[a = 2.\]

\[Ответ:\ a = 2.\]