93. Выполните действия: a) $$12+3\frac{3}{8}-1\frac{5}{6}$$; б) $$7\frac{8}{15}+\left(5\frac{7}{10}-4\right)$$

Решение:

1. \(12+3\frac{3}{8}-1\frac{5}{6} = 15\frac{3}{8}-1\frac{5}{6} = \frac{123}{8}-\frac{11}{6} = \frac{369}{24}-\frac{44}{24} = \frac{325}{24}\)
2. \(7\frac{8}{15}+\left(5\frac{7}{10}-4\right) = 7\frac{8}{15}+1\frac{7}{10} = \frac{113}{15}+\frac{17}{10} = \frac{226}{30}+\frac{51}{30} = \frac{277}{30}\)

Ответ: а) $$\frac{325}{24}$$; б) $$\frac{277}{30}$$.