[tex]\left \{ {{4x-2y=14} \atop {6x-6y=12}} \right.[/tex]
[tex]\left \{ {{2x-y=7} \atop {x-y=2}} \right.[/tex]
[tex](2x-y)-(x-y)=7-2[/tex]
[tex]2x-y-x+y=5[/tex]
[tex]x=5[/tex]
[tex]x-y=2[/tex]
[tex]5-y=2[/tex]
[tex]-y=2-5[/tex]
[tex]-y=-3[/tex]
[tex]y=3[/tex]
