Question

Найдите значение выражения
а) 6/7*4/9*15/16
,Б) 2/3*6/7+8/21*1/4

Answer 1

Пошаговое объяснение:

а)

$\frac{6}{7} \times \frac{4}{9} \times \frac{15}{16} =\frac{6\times 4}{7\times 9}\times \left(\frac{15}{16}\right) =\frac{24}{63}\times \left(\frac{15}{16}\right) =\frac{8}{21}\times \left(\frac{15}{16}\right) =\frac{8\times 15}{21\times 16} =\frac{120}{336} =\frac{5}{14}$

б)

$\frac{2}{3} \times \frac{6}{7} + \frac{8}{21} \times \frac{1}{4} = \frac{2\times 6}{3\times 7}+\frac{8}{21}\times \left(\frac{1}{4}\right) =\frac{12}{21}+\frac{8}{21}\times \left(\frac{1}{4}\right) =\frac{4}{7}+\frac{8}{21}\times \left(\frac{1}{4}\right) =\frac{4}{7}+\frac{8\times 1}{21\times 4} =\frac{4}{7}+\frac{8}{84} =\frac{4}{7}+\frac{2}{21} =\frac{12}{21}+\frac{2}{21} =\frac{12+2}{21} =\frac{14}{21} =\frac{2}{3}$