[tex] \left \{ {{2x+y=7\ \ | *4} \atop {3x-4y=5}} \right. \\\\ \left \{ {{8x+4y=28} \atop {3x-4y=5}} \right. \\+----\\Addition\ method\\\\
11x=33\ \ \ | divide\ by\ 11\\
x=3\\\\y=7-2x\\
y=7-2*3=7-6=1\\\\Solution:\\ \left \{ {{y=1} \atop {x=3}} \right. [/tex]