107. Вычислите.

а) $\frac{4}{5} : (\frac{1}{3} + \frac{2}{15}) \cdot \frac{1}{2} = \frac{4}{5} : (\frac{5}{15} + \frac{2}{15}) \cdot \frac{1}{2} = \frac{4}{5} : \frac{7}{15} \cdot \frac{1}{2} = \frac{4}{5} \cdot \frac{15}{7} \cdot \frac{1}{2} = \frac{4 \cdot 15 \cdot 1}{5 \cdot 7 \cdot 2} = \frac{6}{7}$ б) $\frac{5}{9} \cdot \frac{3}{25} + \frac{4}{9} : \frac{1}{3} = \frac{15}{225} + \frac{4}{9} \cdot 3 = \frac{1}{15} + \frac{4}{3} = \frac{1}{15} + \frac{20}{15} = \frac{21}{15} = 1\frac{6}{15} = 1\frac{2}{5}$ в) $(\frac{2}{11} - \frac{3}{22} + \frac{7}{33}) : \frac{1}{11} = (\frac{12}{66} - \frac{9}{66} + \frac{14}{66}) \cdot 11 = \frac{17}{66} \cdot 11 = \frac{17}{6} = 2\frac{5}{6}$ г) $\frac{15}{16} \cdot \frac{2}{5} : \frac{3}{25} = \frac{30}{80} : \frac{3}{25} = \frac{3}{8} \cdot \frac{25}{3} = \frac{25}{8} = 3\frac{1}{8}$ д) $3\frac{2}{7} : \frac{1}{7} - \frac{1}{2} = \frac{23}{7} : \frac{1}{7} - \frac{1}{2} = \frac{23}{7} \cdot 7 - \frac{1}{2} = 23 - \frac{1}{2} = 22\frac{1}{2}$ е) $\frac{2}{9} : \frac{1}{3} \cdot (\frac{3}{4} - \frac{1}{12}) = (\frac{2}{9} \cdot 3) \cdot (\frac{9}{12} - \frac{1}{12}) = \frac{2}{3} \cdot \frac{8}{12} = \frac{2}{3} \cdot \frac{2}{3} = \frac{4}{9}$