\left \{ {{3x-2y=4} \atop {2y=12-5x}} \right. \\3x-(12-5x)=4\\x=2\\2y=12-5*2\\y=1" alt="\left \{ {{3x-2y=4} \atop {5x+2y=12}} \right. => \left \{ {{3x-2y=4} \atop {2y=12-5x}} \right. \\3x-(12-5x)=4\\x=2\\2y=12-5*2\\y=1" align="absmiddle" class="latex-formula">