So you need to change the position of 8 and take it behind the equals to sign. When you do so the positive 8 Changes to negative 8 and the equation become y = 82 - 8 then when you solve it the answer comes 74.
I think if you take 360 and divide it by 55 thats how many busses they used. Then take that answer and divide it by 13 to find how many vans were used.