1. Найдите значение выражения: a) $$4\frac{2}{5}+3\frac{5}{6}$$; б) $$2\frac{3}{4}-1\frac{5}{6}$$; в) $$\frac{5}{6}-\frac{3}{8}-\frac{1}{12}$$.

a) $$4\frac{2}{5}+3\frac{5}{6} = \frac{22}{5} + \frac{23}{6} = \frac{22 \cdot 6 + 23 \cdot 5}{30} = \frac{132 + 115}{30} = \frac{247}{30} = 8\frac{7}{30}$$ б) $$2\frac{3}{4}-1\frac{5}{6} = \frac{11}{4} - \frac{11}{6} = \frac{11 \cdot 3 - 11 \cdot 2}{12} = \frac{33 - 22}{12} = \frac{11}{12}$$ в) $$\frac{5}{6}-\frac{3}{8}-\frac{1}{12} = \frac{5 \cdot 4 - 3 \cdot 3 - 1 \cdot 2}{24} = \frac{20 - 9 - 2}{24} = \frac{9}{24} = \frac{3}{8}$$ Ответ: а) $$8\frac{7}{30}$$; б) $$\frac{11}{12}$$; в) $$\frac{3}{8}$$