2. a) $$3\frac{5}{12}-2,75+5\frac{5}{6}$$ б) $$3\frac{7}{4}-3,25+1\frac{1}{14}$$

Решение:

1. \( 3\frac{5}{12} - 2,75 + 5\frac{5}{6} = 3\frac{5}{12} - 2\frac{3}{4} + 5\frac{5}{6} = 3\frac{5}{12} - 2\frac{9}{12} + 5\frac{10}{12} = \frac{41}{12} - \frac{33}{12} + \frac{70}{12} = \frac{8+70}{12} = \frac{78}{12} = 6\frac{6}{12} = 6\frac{1}{2} \)
2. \( 3\frac{7}{4} - 3,25 + 1\frac{1}{14} = 3\frac{7}{4} - 3\frac{1}{4} + 1\frac{1}{14} = 3\frac{7}{4} - \frac{13}{4} + 1\frac{1}{14} = \frac{31}{4} - \frac{13}{4} + 1\frac{1}{14} = \frac{18}{4} + 1\frac{1}{14} = 4\frac{2}{4} + 1\frac{1}{14} = 4\frac{1}{2} + 1\frac{1}{14} = 4\frac{7}{14} + 1\frac{1}{14} = 5\frac{8}{14} = 5\frac{4}{7} \)