1. Вычислите: а) 2/3 + 5/8; б) 11/16 − 5/8; в) 6/35 + 3/10; г) 7/12 − 3/8; д) 8/15 − 4/9; е) 3/10 + 4/15.

1. \(\frac{2}{3}+\frac{5}{8}=\frac{16}{24}+\frac{15}{24}=\frac{31}{24}=1\frac{7}{24}\).
2. \(\frac{11}{16}-\frac{5}{8}=\frac{11}{16}-\frac{10}{16}=\frac{1}{16}\).
3. \(\frac{6}{35}+\frac{3}{10}=\frac{12}{70}+\frac{21}{70}=\frac{33}{70}\).
4. \(\frac{7}{12}-\frac{3}{8}=\frac{14}{24}-\frac{9}{24}=\frac{5}{24}\).
5. \(\frac{8}{15}-\frac{4}{9}=\frac{24}{45}-\frac{20}{45}=\frac{4}{45}\).
6. \(\frac{3}{10}+\frac{4}{15}=\frac{9}{30}+\frac{8}{30}=\frac{17}{30}\).

Ответ: а) \(1\frac{7}{24}\); б) \(\frac{1}{16}\); в) \(\frac{33}{70}\); г) \(\frac{5}{24}\); д) \(\frac{4}{45}\); е) \(\frac{17}{30}\).