Вычислите: а) 3/7 + 5/6; б) 5/6 − 1/2; в) 9/10 − 1/3; г) 5/6 − 5/12; д) 11/18 + 1/6; е) 5/12 + 3/4; ж) 4/5 − 7/12.

1. \(\frac{3}{7}+\frac{5}{6}=\frac{18}{42}+\frac{35}{42}=\frac{53}{42}=1\frac{11}{42}\).
2. \(\frac{5}{6}-\frac{1}{2}=\frac{5}{6}-\frac{3}{6}=\frac{2}{6}=\frac{1}{3}\).
3. \(\frac{9}{10}-\frac{1}{3}=\frac{27}{30}-\frac{10}{30}=\frac{17}{30}\).
4. \(\frac{5}{6}-\frac{5}{12}=\frac{10}{12}-\frac{5}{12}=\frac{5}{12}\).
5. \(\frac{11}{18}+\frac{1}{6}=\frac{11}{18}+\frac{3}{18}=\frac{14}{18}=\frac{7}{9}\).
6. \(\frac{5}{12}+\frac{3}{4}=\frac{5}{12}+\frac{9}{12}=\frac{14}{12}=1\frac{1}{6}\).
7. \(\frac{4}{5}-\frac{7}{12}=\frac{48}{60}-\frac{35}{60}=\frac{13}{60}\).

Ответ: а) \(1\frac{11}{42}\); б) \(\frac{1}{3}\); в) \(\frac{17}{30}\); г) \(\frac{5}{12}\); д) \(\frac{7}{9}\); е) \(1\frac{1}{6}\); ж) \(\frac{13}{60}\).