Вычислите: а) 5/6 + 1/4; б) 7/8 − 5/6; в) 3/10 − 4/15; г) 5 − 3 2/7; д) 4/9 · 3/8; е) 5/8 : 9/10; ж) 2 6/7 : 1 3/7; з) 6 3/5 · 10.

1. \(\frac{5}{6}+\frac{1}{4}=\frac{10}{12}+\frac{3}{12}=\frac{13}{12}=1\frac{1}{12}\).

2. \(\frac{7}{8}-\frac{5}{6}=\frac{21}{24}-\frac{20}{24}=\frac{1}{24}\).

3. \(\frac{3}{10}-\frac{4}{15}=\frac{9}{30}-\frac{8}{30}=\frac{1}{30}\).

4. \(5-3\frac{2}{7}=5-\frac{23}{7}=\frac{35}{7}-\frac{23}{7}=\frac{12}{7}=1\frac{5}{7}\).

5. \(\frac{4}{9}\cdot\frac{3}{8}=\frac{12}{72}=\frac{1}{6}\).

6. \(\frac{5}{8}:\frac{9}{10}=\frac{5}{8}\cdot\frac{10}{9}=\frac{50}{72}=\frac{25}{36}\).

7. \(2\frac{6}{7}:1\frac{3}{7}=\frac{20}{7}:\frac{10}{7}=\frac{20}{7}\cdot\frac{7}{10}=2\).

8. \(6\frac{3}{5}\cdot10=\frac{33}{5}\cdot10=66\).

Ответ: а) \(1\frac{1}{12}\); б) \(\frac{1}{24}\); в) \(\frac{1}{30}\); г) \(1\frac{5}{7}\); д) \(\frac{1}{6}\); е) \(\frac{25}{36}\); ж) \(2\); з) \(66\).