Question

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

Part A: How many more dollars is the price of a box of Luke'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 Luke save each month with the change in cereal brand if he buys 6 cereal boxes each month? Show your work.

Answer 1

Part A:
Luke's original box of cereal costs $2 more than the super-saving brand.

y=9(1) 
y=9

11-9=2

Part B:
y=9(6)
y=54

11x6=66

66-54=12

Luke saves $12 each month if he buys 6 boxes of the super-saving brand. 

Answer 2

Answer:

Part A: the original brand of cereal is 2 dollars more expensive than the super saving brand

Part B: Luk save 12 dollars each month

Step-by-step explanation:

One box of the original brand of cereal that luke buys cost 11 dollars.

For know the cost of one box of the super saving brand is necessary to use the equation:

y=9x

Where x is the number of boxes and y is the price. Replacing x for 1, we get:

y=9*(1)=9

then, the price of one box of the super saving brand is 9 dollars. So the difference between the two price says us how many more dollars is the price of a box of luke's original brand and the super saving brand. It is calculated as:

difference=11 dollars - 9 dollars = 2 dollars.

For part b is necessary to know the price of 6 cereal boxes of every brand:

For original brand is calculating by making a multiplication between the cost per box and the number of boxes:

Total cost original Brand = 11 dollars * 6 = 66 dollars

For super saving brand is calculating with the following equation:

y=9x

y=9*6 = 54 dollars

Then the total cost of the super saving brand by month is 54 dollars

So the difference between the two price says us how much money Luke save every month. It is calculated as:

Difference= 66 dollars - 54 dollars = 12 dollars