Question

5x-7y=-2
-5x-10y=-15

Answer 1

{5x-7y=-2

{-5x-10y=-15 (+)

5x-5x-7y-10y=-17

-17y=-17 /:(-17)

y=1

5x-7 *1=-2

5x-7=-2 /+7

5x=5 /:5

x=1

Solution: (1; 1)