Question

Yani buys a certain brand of cereal that costs $10 per box. Yani 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 = 7x
Part A: How many more dollars is the price of a box of Yani's original brand of cereal than the price of a box of the super-saving cereal?
Show your work.
Part B: How much money does Yani save each month with the change in cereal brand if he buys 5 cereal boxes each month? Show your
work.

Answer 1

Answer:

A) Original price : y =10.x

Cheaper brand : y = 7x

The original box is $3 more than the cheap one.  

Proof: Suppose 1 box is bought of each (x=1),Original will cost $10 & the Cheaper Price is $7

B) Each time he buys a cheap brand he save $3 ($10-$7).

On 5 cheap boxes, He would save $3 x 5 boxes = $15.

Step-by-step explanation:

Part A: The price of the first cereal that Yani bought was $10 and he new cereal is $7.

$10 - $7 = $3. The original box of cereal was $3 more than the super- saving cereal.

Part B: Yani will save $15 each month.

With the $10 cereal he used to pay $50 per month. Now with the super-saving cereal, he will now pay $35 per month.

So we need to subtract $50 - $35 = $15

Answer 2

A. Yani's original brand of cereal is $3 more expensive.

His old brand cost $10 a box. His new brand cost can be determined by the slope of y=7x, thus it is $7. The difference between 10 and 7 is 3, thus there is a $3 difference.

B. Yani would save $15 per month buying the super-saving cereal.

Original: y = 10x

y=10(5)

y = $50

Super-saving: y = 7x

y=7(5)

y = $35

If Yani were to buy 5 boxes of the original cereal, he would spend $50. If she were to buy 5 boxes of the super-saving cereal, he would spend $35. The difference between 50 and 35 is 15, thus he would save $15 per month.