Question

x*3/5+x*2/7=31/70

* là dấu nhân,/ là gạch ngang phân số 

nhớ ghi cách giải nhé

Answer 1

x*3/5+x*2/7=31/70

x*(3/5+2/7) =31/70

x*31/35      =31/70

         x       =31/70 :31/35

         x        = 1/2

Answer 2

\(x.\frac{3}{5}+x.\frac{2}{7}=\frac{31}{70}\)

\(x\left(\frac{3}{5}+\frac{2}{7}\right)=\frac{31}{70}\)

\(x\left(\frac{21}{35}+\frac{10}{35}\right)=\frac{31}{70}\)

\(\frac{31}{35}x=\frac{31}{70}\)

\(x=\frac{31}{70}:\frac{31}{35}\)

\(x=\frac{31}{70}.\frac{35}{31}\)

\(x=\frac{35}{70}\)

\(x=\frac{1}{2}\)

vay \(x=\frac{1}{2}\)