Question

tìm x 

5/7 - 2/3 . x = 4/5

Answer 1

2/3x=5/7-4/5

2/3x=-3/35

x=-3/35 : 2/3

x=-9/70

Vậy x=-9/70

Answer 2

\(\frac{5}{7}-\frac{2}{3}.x=\frac{5}{4}\)

\(\frac{2}{3}.x=\frac{5}{7}-\frac{5}{4}\)

\(\frac{2}{3}.x=\frac{-15}{28}\)

\(x=\frac{-15}{28}:\frac{2}{3}\)

\(x=\frac{-45}{56}\)

nha bn

Answer 3

5 / 7 - 2/3 .x = 4/5 

1/21 .x = 4/5

         x = 4/5 : 1/21 

         x = 4/5. 21/1 

         x = 84/5