Step-by-step explanation:
x-3y=18 were going to put the x's on one side and the y's one side
-3y=18-x so to get y by itself where going to have to divide -3y by -3 but remember what ever you do to one side u do to the other
-3y/-3 = 18/-3-x/-3 - with a - is +
y= -6 + 1x/3
~batmans wife dun dun dun.....