8) $\left(\frac{10}{21}-\frac{25}{28}\right):\left(-\frac{11}{14}+\frac{21}{35}\right)$;

Question

$Фото задания: 8) $\left(\frac{10}{21}-\frac{25}{28}\right):\left(-\frac{11}{14}+\frac{21}{35}\right)$;$ Фото задания

Accepted Answer

$\frac{10}{21}-\frac{25}{28}=\frac{40}{84}-\frac{75}{84}=-\frac{35}{84}=-\frac{5}{12}$.

$-\frac{11}{14}+\frac{21}{35}=-\frac{11}{14}+\frac35=-\frac{55}{70}+\frac{42}{70}=-\frac{13}{70}$.

$-\frac{5}{12}:\left(-\frac{13}{70}\right)=\frac{5}{12}\cdot\frac{70}{13}=\frac{175}{78}$.

Ответ: $\frac{175}{78}=2\frac{19}{78}$.

8) \(\left(\frac{10}{21}-\frac{25}{28}\right):\left(-\frac{11}{14}+\frac{21}{35}\right)\);