Sue buys a certain brand of cereal that costs $12 per box. Sue 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 = 8x

Part A: How many more dollars is the price of a box of Sue's original brand of cereal than the price of a box of the super-saving brand? Show your work.

Part B: How much money does Sue save each month with the change in cereal brand if she buys 4 cereal boxes each month? Show your work.