Задание 3. Найдите значение выражения: а) \(\left(-\frac{5}{12}-\frac{13}{20}\right)^2\cdot\left(-1\frac{13}{32}\right)\); б) \(\left(-\frac{2}{3}-\frac{5}{6}\right)^3\cdot\left(-3\frac{5}{9}\right)\).

а) \( -\frac{5}{12}-\frac{13}{20}=-\frac{25}{60}-\frac{39}{60}=-\frac{64}{60}=-\frac{16}{15}.\)

\(\left(-\frac{16}{15}\right)^2\cdot\left(-1\frac{13}{32}\right)=\frac{256}{225}\cdot\left(-\frac{45}{32}\right)=-\frac{8\cdot45}{225}=-\frac{8}{5}.\)

б) \( -\frac{2}{3}-\frac{5}{6}=-\frac{4}{6}-\frac{5}{6}=-\frac{9}{6}=-\frac{3}{2}.\)

\(\left(-\frac{3}{2}\right)^3\cdot\left(-3\frac{5}{9}\right)=-\frac{27}{8}\cdot\left(-\frac{32}{9}\right)=12.\)

Ответ: а) \(-\frac{8}{5}\); б) \(12\).