Ответ:
\(7\cdot2\frac{6}{7}=7\cdot\frac{20}{7}=20\).
\(\frac{7}{9}-\frac{9}{4}=\frac{28-81}{36}=-\frac{53}{36}\).
\(\frac{53}{12}:\left(-\frac{53}{36}\right)=-3\).
\(20-3=17\).
Ответ: \(17\)
\(7\cdot2\frac{6}{7}=7\cdot\frac{20}{7}=20\).
\(\frac{7}{9}-\frac{9}{4}=\frac{28-81}{36}=-\frac{53}{36}\).
\(\frac{53}{12}:\left(-\frac{53}{36}\right)=-3\).
\(20-3=17\).
Ответ: \(17\)