1. Вычислите: а) 14 − 7 2/21; б) 6 5/8 + 5 3/8; в) 19 2/15 − 3 4/15; г) 2/7 + 5/6; д) 2/3 − 1/12; е) 9/8 · 16/27; ж) (2/5)³; з) 42/25 : 14/45; и) 36/7 : 6; к) 56 : 7/5.

1. а) \(14-7\frac{2}{21}=14-\frac{149}{21}=\frac{294-149}{21}=\frac{145}{21}=6\frac{19}{21}\).
2. б) \(6\frac{5}{8}+5\frac{3}{8}=11+\frac{8}{8}=12\).
3. в) \(19\frac{2}{15}-3\frac{4}{15}=16-\frac{2}{15}=15\frac{13}{15}\).
4. г) \(\frac{2}{7}+\frac{5}{6}=\frac{12}{42}+\frac{35}{42}=\frac{47}{42}=1\frac{5}{42}\).
5. д) \(\frac{2}{3}-\frac{1}{12}=\frac{8}{12}-\frac{1}{12}=\frac{7}{12}\).
6. е) \(\frac{9}{8}\cdot\frac{16}{27}=\frac{2}{3}\).
7. ж) \(\left(\frac{2}{5}\right)^3=\frac{2^3}{5^3}=\frac{8}{125}\).
8. з) \(\frac{42}{25}:\frac{14}{45}=\frac{42}{25}\cdot\frac{45}{14}=\frac{27}{5}=5\frac{2}{5}\).
9. и) \(\frac{36}{7}:6=\frac{36}{7}\cdot\frac{1}{6}=\frac{6}{7}\).
10. к) \(56:\frac{7}{5}=56\cdot\frac{5}{7}=40\).

Ответ: а) \(6\frac{19}{21}\); б) \(12\); в) \(15\frac{13}{15}\); г) \(1\frac{5}{42}\); д) \(\frac{7}{12}\); е) \(\frac{2}{3}\); ж) \(\frac{8}{125}\); з) \(5\frac{2}{5}\); и) \(\frac{6}{7}\); к) \(40\).