Вычислите. 6 вариант: 1) 1/3 + 1/5 =; 2) 6/7 − 1/3 =; 3) 1/2 · 7/10 =; 4) 3/4 : 1/8 =; 5) 1 3/7 + 1 5/6 =; 6) 2 1/4 − 2/3 =; 7) 1 1/2 · 2 4/5 =; 8) 4 1/6 : 2 2/5 =; 9) 1/6 + 1 =; 10) 3 − 2/3 =; 11) 4 · 2/8 =; 12) 5/8 : 5 =.

1. \(\frac{1}{3}+\frac{1}{5}=\frac{5}{15}+\frac{3}{15}=\frac{8}{15}\).
2. \(\frac{6}{7}-\frac{1}{3}=\frac{18}{21}-\frac{7}{21}=\frac{11}{21}\).
3. \(\frac{1}{2}\cdot\frac{7}{10}=\frac{7}{20}\).
4. \(\frac{3}{4}:\frac{1}{8}=\frac{3}{4}\cdot 8=6\).
5. \(1\frac{3}{7}+1\frac{5}{6}=2+\frac{18}{42}+\frac{35}{42}=2\frac{53}{42}=3\frac{11}{42}\).
6. \(2\frac{1}{4}-\frac{2}{3}=\frac{9}{4}-\frac{2}{3}=\frac{27}{12}-\frac{8}{12}=\frac{19}{12}=1\frac{7}{12}\).
7. \(1\frac{1}{2}\cdot2\frac{4}{5}=\frac{3}{2}\cdot\frac{14}{5}=\frac{42}{10}=4\frac{1}{5}\).
8. \(4\frac{1}{6}:2\frac{2}{5}=\frac{25}{6}:\frac{12}{5}=\frac{25}{6}\cdot\frac{5}{12}=\frac{125}{72}=1\frac{53}{72}\).
9. \(\frac{1}{6}+1=\frac{7}{6}=1\frac{1}{6}\).
10. \(3-\frac{2}{3}=\frac{9}{3}-\frac{2}{3}=\frac{7}{3}=2\frac{1}{3}\).
11. \(4\cdot\frac{2}{8}=\frac{8}{8}=1\).
12. \(\frac{5}{8}:5=\frac{5}{8}\cdot\frac{1}{5}=\frac{1}{8}\).

Ответ: 1) \(\frac{8}{15}\); 2) \(\frac{11}{21}\); 3) \(\frac{7}{20}\); 4) \(6\); 5) \(3\frac{11}{42}\); 6) \(1\frac{7}{12}\); 7) \(4\frac{1}{5}\); 8) \(1\frac{53}{72}\); 9) \(1\frac{1}{6}\); 10) \(2\frac{1}{3}\); 11) \(1\); 12) \(\frac{1}{8}\).