Let's use the addition/subtraction method.
Suppose we wish to eliminate variable x.
Mult the first eqn by 5: 10x - 15y = 15
Mult the 2nd eqn by -2: -10x+ 4y = -8
Add these two equations together: -11y = 7, and y = -7/11.
Subst. -7/11 for y in either given equation and find x.
Then your solution is (x,y) (subst. the values we've found for x and y).
