Rút gọn

A: $49\frac{8}{23}-\left(5\frac{7}{32}+14\frac{8}{23}\right)$
B: $71\frac{38}{45}-\left(43\frac{8}{45}-1\frac{17}{57}\right)$
C: $\left(19\frac{5}{8}÷\frac{7}{11}-13\frac{1}{4}÷\frac{7}{12}\right)·\frac{4}{5}$