Question

Hey I'm kinda stuck on this one, can I get some help?

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.

Answer 1

Because the new function is y = 8x, we know each box costs $8.

The original brand costs $12 per box, so the new brand is $4 cheaper.

To find out how much we'd save if we bought 4 boxes, we can replace the value of x with 4 in each equation.

y = 12x

y = 12(4)

y = 48

y = 8x

y = 8(4)

y = 32

On buying 4 boxes, we'd save $16 with the new brand.