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