Multiply the second equation by -1 to make it x+y=4
Now you have to add the together
-x- 4y=14
+ x+ y= 4
The x's cancel out leaving you with
-3y=18
Divide -3 on both sides
y=-6
Now plug in y to one of the equations
-x-4(-6)=14
-x+24=14
subtract 24 on both sides
-x=-10
Divide by -1 on both sides to make x positive
x=10
(10,-6)