mik viết sai đáp an á = 0 nha

\(\left(\dfrac{-3}{5}+\dfrac{5}{6}\right):\dfrac{4}{7}+\left(\dfrac{1}{6}+\dfrac{2}{-5}\right):\dfrac{4}{7}\)
=\(\left(\dfrac{-18}{30}+\dfrac{25}{30}\right).\dfrac{7}{4}+\left(\dfrac{5}{30}+\dfrac{-12}{30}\right).\dfrac{7}{4}\)
= \(\dfrac{7}{30}.\dfrac{7}{4}+\dfrac{-7}{30}.\dfrac{7}{4}\)
= \(\dfrac{7}{4}.\left(\dfrac{7}{30}+\dfrac{-7}{30}\right)\)
= \(\dfrac{7}{4}\)