Question

Let d represent the number of $2 decreases i price. Let r be the company’s revenue. Write a quadratic function that reflects the company’s revenue.

Answer 1

Let d be the number of $2 decreases, and r be the company´s revenue, then the company can sell:

`800+40d`

cellphones per week at a price of:

`80-2d`

dollars.

Therefore, the quadratic equation that represents the revenue is:

`(800+40d)(80-2d)\text{.}`

Now, graphing the above equation we get:

From the above graph, we can determine the vertex and the vertex gives us for which value of d the company gets the maximum revenue.

The company should charge $80-10($2)=$80-$20=$60.