Question

The formula p=8n-30 gives the profit p when a number of items n are each sold at $8 and expenses totaling $30 are subtracted

A. If the profit is $170.00, how many items were bought

B. If the same number of items were bought but the expenses changed to $40, would the profit increase or decrease, and by how much

Answer 1

A:
p = 8n - 30
170.00 = 8n - 30               add 30 to each side
200.00 = 8n            divide by 8
25 = n              25 items were bought.

B:
The profite would decrese  

8(25) - 40
200 - 40
160        original was 170 but it decreased by 10$

hope this helped :)

Answer 2

Answer with explanation:

A)

The formula that is used to represent the profit when n items are sold and there are expenses of $ 30 is given by:

                       p=8n-30

Now we are asked to find the value of n when  p=170

i.e.

170=8n-30

on adding both side by 30 we get:

8n=170+30

i.e.

8n=200

i.e.

n=200/8

i.e.

n=25

Hence, the number of items bought= 25

B)

Now, if the expenses are changed to $ 40

Then the profit function is given by:

          p=8n-40

Hence, when n=25 we have:

p=8×25-40

i.e.

p=200-40

i.e.

p=160

Hence, the profit when the expenses changed to $ 40 is: $ 160

This means that the profit decreases.

and the difference in the profit is:  170-160

                                                    = $ 10

This means that the profit decreases by $ 10.