Вычислите:
а) $\frac{6}{7} * \frac{4}{9} * \frac{15}{16}$;
б) $\frac{8}{21} * \frac{1}{4} + \frac{2}{3} : \frac{7}{6}$.
$\frac{6}{7} * \frac{4}{9} * \frac{15}{16} = \frac{1}{7} * \frac{1}{1} * \frac{5}{2} = \frac{5}{14}$
$\frac{8}{21} * \frac{1}{4} + \frac{2}{3} : \frac{7}{6} = \frac{8}{21} * \frac{1}{4} + \frac{2}{3} * \frac{6}{7} = \frac{2}{21} * \frac{1}{1} + \frac{2}{1} * \frac{2}{7} = \frac{2}{21} + \frac{4}{7} = \frac{2}{21} + \frac{12}{21} = \frac{14}{21} = \frac{2}{3}$
Пожауйста, оцените решение
