2. Вычислите: 1) 5/6 + 2/7; 2) 15/16 − 3/4; 3) 3/20 + 7/15; 4) 13/16 − 7/12.

1. \(\frac{5}{6}+\frac{2}{7}=\frac{35}{42}+\frac{12}{42}=\frac{47}{42}=1\frac{5}{42}\).
2. \(\frac{15}{16}-\frac{3}{4}=\frac{15}{16}-\frac{12}{16}=\frac{3}{16}\).
3. \(\frac{3}{20}+\frac{7}{15}=\frac{9}{60}+\frac{28}{60}=\frac{37}{60}\).
4. \(\frac{13}{16}-\frac{7}{12}=\frac{39}{48}-\frac{28}{48}=\frac{11}{48}\).

Ответ: 1) \(1\frac{5}{42}\); 2) \(\frac{3}{16}\); 3) \(\frac{37}{60}\); 4) \(\frac{11}{48}\).