86. Выполните действие: а) 2 5/8 − 1 3/10; б) 3 3/5 + 1 5/6; в) 5 1/14 + 1 16/21; г) 4 4/9 − 1 5/6.

1. \(2\frac{5}{8}-1\frac{3}{10}=\frac{21}{8}-\frac{13}{10}=\frac{53}{40}=1\frac{13}{40}\).
2. \(3\frac{3}{5}+1\frac{5}{6}=\frac{18}{5}+\frac{11}{6}=5\frac{13}{30}\).
3. \(5\frac{1}{14}+1\frac{16}{21}=\frac{71}{14}+\frac{37}{21}=6\frac{5}{6}\).
4. \(4\frac{4}{9}-1\frac{5}{6}=\frac{40}{9}-\frac{11}{6}=2\frac{11}{18}\).

Ответ: а) \(1\frac{13}{40}\); б) \(5\frac{13}{30}\); в) \(6\frac{5}{6}\); г) \(2\frac{11}{18}\).