Найдите значение выражения:
а) $(\frac{5}{6} - \frac{2}{3}) : \frac{8}{9}$;
б) $\frac{2}{3} : (\frac{2}{5} + \frac{4}{15})$;
в) $10 : \frac{2}{5} - \frac{3}{10}$;
г) $(1\frac{1}{2} + \frac{3}{8}) : 3$.
$(\frac{5}{6} - \frac{2}{3}) : \frac{8}{9} = (\frac{5}{6} - \frac{4}{6}) * \frac{9}{8} = \frac{1}{6} * \frac{9}{8} = \frac{1}{2} * \frac{3}{8} = \frac{3}{16}$
$\frac{2}{3} : (\frac{2}{5} + \frac{4}{15}) = \frac{2}{3} : (\frac{6}{15} + \frac{4}{15}) = \frac{2}{3} : \frac{10}{15} = \frac{2}{3} : \frac{2}{3} = \frac{2}{3} * \frac{3}{2} = 1$
$10 : \frac{2}{5} - \frac{3}{10} = 10 * \frac{5}{2} - \frac{3}{10} = 5 * \frac{5}{1} - \frac{3}{10} = 25 - \frac{3}{10} = 24\frac{7}{10}$
$(1\frac{1}{2} + \frac{3}{8}) : 3 = (1\frac{4}{8} + \frac{3}{8}) * \frac{1}{3} = 1\frac{7}{8} * \frac{1}{3} = \frac{15}{8} * \frac{1}{3} = \frac{5}{8} * \frac{1}{1} = \frac{5}{8}$