5. Выполните действия: а) 3/7 + 5/14; б) 8/9 − 7/12; в) 2 1/8 + 3 5/12; г) 5 13/15 + 1 7/12; д) 3 3/8 − 3 5/6.

1. \(\frac{3}{7}+\frac{5}{14}=\frac{6}{14}+\frac{5}{14}=\frac{11}{14}\).
2. \(\frac{8}{9}-\frac{7}{12}=\frac{32}{36}-\frac{21}{36}=\frac{11}{36}\).
3. \(2\frac{1}{8}+3\frac{5}{12}=5+\frac{3}{24}+\frac{10}{24}=5\frac{13}{24}\).
4. \(5\frac{13}{15}+1\frac{7}{12}=6+\frac{52}{60}+\frac{35}{60}=6\frac{87}{60}=7\frac{9}{20}\).
5. \(3\frac{3}{8}-3\frac{5}{6}=\frac{27}{8}-\frac{23}{6}=\frac{81}{24}-\frac{92}{24}=-\frac{11}{24}\).

Ответ: а) \(\frac{11}{14}\); б) \(\frac{11}{36}\); в) \(5\frac{13}{24}\); г) \(7\frac{9}{20}\); д) \(-\frac{11}{24}\).