4. Вычислите: 1) \(2\frac{3}{4}+3\frac{2}{5}\); 2) \(2\frac{4}{9}-2\frac{1}{6}\); 3) \(8\frac{3}{10}-4\frac{5}{6}\).

1. \(2\frac34+3\frac25=5+\frac34+\frac25=5+\frac{15}{20}+\frac8{20}=5\frac{23}{20}=6\frac3{20}\).
2. \(2\frac49-2\frac16=\frac49-\frac16=\frac8{18}-\frac3{18}=\frac5{18}\).
3. \(8\frac3{10}-4\frac56=4+\frac3{10}-\frac56=4+\frac9{30}-\frac{25}{30}=3\frac{14}{30}=3\frac7{15}\).

Ответ: 1) \(6\frac3{20}\); 2) \(\frac5{18}\); 3) \(3\frac7{15}\).