3x - 4y = 18x + 3y = -7
3x-4y=18 +3x +3x------------------4y=3x+18÷-4 ÷-4----------------y=-3/4x-6x+3y=-7-x -x------------3y=-x-7 ÷3 ÷3--------------y=-x-7/3I think but not sure :)