Question

Tìm x

a) 2/5 . x = 1/2 + 6/8

b) 20/7 - x = 19/7 : 3/2

Giúp nốt 2 câu 

Answer 1

a) \(\dfrac{2}{5}\cdot x=\dfrac{1}{2}+\dfrac{6}{8}\)

    \(\dfrac{2}{5}\cdot x=\dfrac{5}{4}\)

          \(x=\dfrac{5}{4}\div\dfrac{2}{5}\)

          \(x=\dfrac{25}{8}\)

b) \(\dfrac{20}{7}-x=\dfrac{19}{7}\div\dfrac{3}{2}\)

    \(\dfrac{20}{7}-x=\dfrac{19}{7}\cdot\dfrac{2}{3}\)

    \(\dfrac{20}{7}-x=\dfrac{38}{21}\)

             \(x=\dfrac{20}{7}-\dfrac{28}{21}\)

             \(x=\dfrac{22}{21}\)

Answer 2

a) x=25/8

b)=22/21

Answer 3

a) x=25/8

b)=22/21

Answer 4

a) \(x=\frac{25}{8}\)

b)\(x=\frac{22}{21}\)

Answer 5

a) x = 25/8

b) x = 22/21