Question

A store charges their customers based on the number of items that they buy. Jane bought four items and was charged $15 and George bought twelve items and was charged $39. Write a function to model the cost based on the number of items you buy. Then determine how much you are charged if you purchase 22 items.

Answer 1

Use a rational expression to determine that F(x)= 3x+3=33
By taking the +3 and moving it over to the other side, it would give you a negative 3, so 33-3= 30 and 3 multiplied by x equals 30. Our answer would be x=10

Answer 2

The function is
`y=3x+3`

She would be charged $69 dollars for 22 items.

Explanation:

We are given that,

Jane was charged $15 for buying 4 items.

Jane was charged $39 for buying 12 items.

Since, we have,

15 = 3 × 4 + 3

39 = 3 × 12 + 3

So, the function modeled for this situation will be,

Let, y = amount of money charged in dollars and x = number of items bought.

Then, the function is
`y=3x+3`.

Further, when she purchases 22 items, the cost would be,

`y=3* 22+3` implies
`y=66+3` i.e. y= 69 (dollars)

Hence, she would be charged $69 dollars for 22 items.