Вычислите:
а) $\frac{8}{9} * \frac{3}{4} - (\frac{5}{6} - \frac{1}{4})$;
б) $\frac{3}{5} + \frac{4}{5} * \frac{3}{7} + \frac{6}{7}$;
в) $(\frac{2}{5} - \frac{2}{7}) : \frac{2}{7} * \frac{2}{5}$;
г) $(\frac{5}{6} - \frac{3}{10}) : (\frac{3}{10} + \frac{2}{15})$.
$\frac{8}{9} * \frac{3}{4} - (\frac{5}{6} - \frac{1}{4}) = \frac{2}{3} * \frac{1}{1} - \frac{10 - 3}{12} = \frac{2}{3} - \frac{7}{12} = \frac{8 - 7}{12} = \frac{1}{12}$
$\frac{3}{5} + \frac{4}{5} * \frac{3}{7} + \frac{6}{7} = \frac{3}{5} + \frac{12}{35} + \frac{6}{7} = \frac{21 + 12 + 30}{35} = \frac{63}{35} = \frac{9}{5} = 1\frac{4}{5}$
$(\frac{2}{5} - \frac{2}{7}) : \frac{2}{7} * \frac{2}{5} = (\frac{2}{5} - \frac{2}{7}) * \frac{7}{2} * \frac{2}{5} = \frac{14 - 10}{35} * \frac{7}{5} = \frac{4}{35} * \frac{7}{5} = \frac{4}{5} * \frac{1}{5} = \frac{4}{25}$
$(\frac{5}{6} - \frac{3}{10}) : (\frac{3}{10} + \frac{2}{15}) = \frac{25 - 9}{30} : \frac{9 + 4}{30} = \frac{16}{30} : \frac{13}{30} = \frac{16}{30} * \frac{30}{13} = \frac{16}{13} = 1\frac{3}{13}$
Пожауйста, оцените решение
