Đề yêu cầu gì em?
\(\dfrac{4}{5}+\dfrac{5}{7}:x=\dfrac{1}{6}\\ \dfrac{5}{7}:x=\dfrac{1}{6}-\dfrac{4}{5}\\ \dfrac{5}{7}:x=-\dfrac{19}{30}\\ x=\dfrac{5}{7}:\left(-\dfrac{19}{30}\right)\\ x=\dfrac{5}{7}\times\dfrac{-30}{19}=-\dfrac{150}{133}\)
\(\dfrac{4}{5}\)+\(\dfrac{5}{7}\):x=\(\dfrac{1}{2}\)
\(\dfrac{5}{7}\):x=\(\dfrac{1}{2}\)-\(\dfrac{4}{5}\)
\(\dfrac{5}{7}\):x=\(-\dfrac{3}{10}\)
x=\(\dfrac{5}{7}\):(\(-\dfrac{3}{10}\))
x=-\(\dfrac{50}{21}\)