=>[tex]\left\{\begin{matrix} 5.(2+x)=2.(5+y) & \\ x+y=14 & \end{matrix}\right. \Leftrightarrow \left\{\begin{matrix} 5x=2y & \\ x=14-y& \end{matrix}\right. \Leftrightarrow \left\{\begin{matrix} 70-5y=2y & \\ x=14-y& \end{matrix}\right.\Leftrightarrow \left\{\begin{matrix} y=10 & \\ x=4& \end{matrix}\right.[/tex]