Luke buys a certain brand of cereal that costs $11 per box. Luke changes to a super-saving brand of the same size. The equation shows the price, y, as a function of the number of boxes, x, for the new brand.

y = 9x



How much money does Luke save after buying 5 boxes? (Hint: Find the cost of 5 boxes for the original box of cereal and for the new box. Find the difference in cost)