1. Вычислите: а) 6 5/6 + 2 3/8; б) 3 4/7 − 2 3/5.

а) \(6\frac{5}{6}+2\frac{3}{8}=8+\frac{5}{6}+\frac{3}{8}=8+\frac{20}{24}+\frac{9}{24}=8+\frac{29}{24}=9\frac{5}{24}\).

б) \(3\frac{4}{7}-2\frac{3}{5}=1+\frac{4}{7}-\frac{3}{5}=1+\frac{20}{35}-\frac{21}{35}=1-\frac{1}{35}=\frac{34}{35}\).

Ответ: а) \(9\frac{5}{24}\); б) \(\frac{34}{35}\).