To solve by elimination, you add or subtract the 2 equations to get rid of one of the variables. Since one equation has a 5x term and the other has a -5x term, if we add the two questions together, we can eliminate x.

-5x + 2y = 13

+ 5x + y = -1

The x terms drop out and you're left with:

2y + y = 13 + -1

3y = 12

y = 4

Now, you substitute y into either one of the original equations to get x.