Найдите произведение дробей: а) 2/3 и 7/1; б) 5/6 и 9/20; в) 3/4 и 8/21; г) 5/16 и 8/15....

А) $\frac{2}{3} * \frac{7}{1} = \frac{2*7}{3*1} = \frac{14}{3} =4 \frac{2}{3}$

б) $\frac{5}{6} * \frac{9}{20} = \frac{5*9}{6*20} = \frac{45}{120} = \frac{3}{8}$

в) $\frac{3}{4} * \frac{8}{21} = \frac{3*8}{4*21} = \frac{24}{84} = \frac{2}{7}$

г) $\frac{5}{16} * \frac{8}{15} = \frac{5*8}{16*15} = \frac{40}{240} = \frac{1}{6}$