{-2x-5y=13
{2x-5y=17 (+)
-2x+2x-5y-5y=13+17
-10y=30 /:(-10)
y=-3
2x-5y=17
2x-5*(-3)=17
2x+15=17
2x=2
x=1
Solution: (1; -3)
