Выполни деление: -7 6/7:(-9 3/7).

\[- 7\frac{6}{7}\ :\left( - 9\frac{3}{7} \right) = \frac{55}{7}\ :\frac{66}{7} =\]

\[= \frac{55}{7} \cdot \frac{7}{66} = \frac{5 \cdot 11 \cdot 7}{7 \cdot 11 \cdot 6} = \frac{5}{6}\]