Question

At a pet store the total cost of 8 pounds of Brand X dog food and 1 pound of Brand Y dog food is $8.40 including tax. Total cost of 16 pounds of Brand X dog food and 8 pounds of Brand Y dog food is $24 including tax. What is the price per pound of Brand Y?

Answer 1

Let x= price per lb of X Brand dog food
Let y= price per lb of Y Brand dog food.

Now set up your equations from the information you have provided.

8x + y = 8.40
16x + 8 y = 24.00

we will use the elimination process
divide the 2nd equation by 8 and place the two equations so the can be subtracted.

8x + y = 8.40
2x + y = 3.00 (2nd equation divided by 8) subtract
--------------------
6x = 5.40
x=.90 or 90 cents
substitute this value for x in the first equation above and get $1.20 for Brand y

Answer 2

Any questions schulte?

Answer 3

We substituted X for the first equation and got 10.2??

Answer 4

Let me check 8x + y =8.40
substitute solution for x
8(.90) + y =8.40 substituting for x
7.20 + y = 8.40

solving for y
y=8.40 - 7.20 how did you get 10.2?

Answer 5

It looks like it is 1.20 a pound.

Answer 6

Ya we got it Thanks!

Answer 7

Good do you understand the elimination process?

Answer 8

Yes we do!(:

Answer 9

Good and good luck with your studies

Answer 10

thank you ! you too