As far as I can remember teacher from Kindergarten, Primary, Secondary, and Intermediate they always emphasize that in Math specially in solving problems the answer must be in ORDER and it's proper place. It's not in scramble order. So, I think there is one simple RULE in Math all the answers it MUST be in order all the time. Because if not, your answer will be wrong. Formula is a formula, and you can never scramble your answer or else everything is wrong.