3. Выполните действия: а) 3 7/8 + 2 5/12; б) 4 9/14 + 3 4/21; в) 8 8/15 − 4 9/20; г) 7 1/10 − 3 1/6.

1. \(3\frac{7}{8}+2\frac{5}{12}=5+\frac{21}{24}+\frac{10}{24}=5+\frac{31}{24}=7\frac{7}{24}\).
2. \(4\frac{9}{14}+3\frac{4}{21}=7+\frac{27}{42}+\frac{8}{42}=7\frac{35}{42}=7\frac{5}{6}\).
3. \(8\frac{8}{15}-4\frac{9}{20}=4+\frac{32}{60}-\frac{27}{60}=4\frac{5}{60}=4\frac{1}{12}\).
4. \(7\frac{1}{10}-3\frac{1}{6}=4+\frac{1}{10}-\frac{1}{6}=4-\frac{1}{15}=3\frac{14}{15}\).

Ответ: а) \(7\frac{7}{24}\); б) \(7\frac{5}{6}\); в) \(4\frac{1}{12}\); г) \(3\frac{14}{15}\).