so u want to get rid of y right?
ok.. so these r the equations:
-x+y=4
x+3y=4
now the easiest way we can go is by multiplying the first equation by negative 3 to cancel out the y's
so it would look like this:
-3(-x+y=4) => 3x-3y=-12
no we can eliminate the y's
(3x-3y=-12) +(x+3y=4) = 4x=-8
now divide by 4 so we can get x by itself
4x=8
x=2
we have x. plug in to 2nd equation to solve for y
(2)+3y=4
-2 -2
3y=2
y=2/3
hope that helps :)
