Ответ:

а)

\(3\frac{2}{3}=\frac{11}{3}\), \(4\frac{2}{5}=\frac{22}{5}\).

\(\frac{11}{3}-\frac{7}{15}+\frac{22}{5}\cdot\frac{1}{3}=\frac{55}{15}-\frac{7}{15}+\frac{22}{15}=\frac{70}{15}=\frac{14}{3}=4\frac{2}{3}\).

б)

\((50,027-9,827):20+2\cdot0,45=40,2:20+0,9=2,01+0,9=2,91\).

в)

\(4\frac{1}{2}\cdot\frac{8}{9}-5\frac{1}{3}:10\frac{2}{3}=\frac{9}{2}\cdot\frac{8}{9}-\frac{16}{3}:\frac{32}{3}\).

\(\frac{9}{2}\cdot\frac{8}{9}=4\), \(\frac{16}{3}:\frac{32}{3}=\frac{1}{2}\).

\(4-\frac{1}{2}=3\frac{1}{2}\).

Ответ: а) \(4\frac{2}{3}\); б) 2,91; в) \(3\frac{1}{2}\).