Question

Colleen plans to print x pictures from her camera at a drug store. The expression $0.2x represents the cost of developing the pictures if she is not a member of the store’s photography club. If she is a member, then the total cost is given by $0.15x + $10. How much more will Colleen pay by not being a member if she develops 350 pictures

Answer 1

$7.5.

Explanation:

We have been given that Colleen plans to print x pictures from her camera at a drug store.

The difference of cost for non-member and member would be difference of both expressions as:

`0.2x-(0.15x+10)=0.05x-10`

To find the difference for developing 350 pictures without being member and non-member, we will substitute
`x=350` in expression
`0.05x-10`:

`0.05(350)-10=17.5-10=7.5`

Therefore, Colleen will pay $7.5, while not being a member and developing 350 pictures.

Answer 2

$7.5

Explanation:

If Colleen develops 350 pictures (x):

1. If member, cost is:

`0.15x + 10\\=0.15(350)+10\\=62.5`

2. If not a member, cost is:

`0.2x\\=0.2(350)\\=70`

Hence, Colleen pays 70 - 62.5 = 7.5 more by not being a member.