[tex] \left \{ {{5x+y=0\ \ | *(-2)} \atop {5x+2y=30}} \right. \\\\ \left \{ {{-10x-2y=0} \atop {5x+2y=30}} \right. \\+-----\\Elimination\ method\\\\
5x=30\ \ | divide\ by \ 5\\\\
x=6\\\\y=-5x=-5*6=-30\\\\Solution:\\ \left \{ {{y=-30} \atop {x=6}} \right. [/tex]
