Question

How much more profit does he earn selling 15 items than 5 items?

Answer 1

Given that:

`P=0.2x^3-10`

Substitute 15 for x in the equation of P to find the profit earned by selling 15 items.

`\begin{gathered} P(15)=0.2(15)^3-10 \\ =665 \end{gathered}`

Substitute 5 for x in the equation of P to find the profit earned by selling 5 items.

`\begin{gathered} P(5)=0.2(5)^3-10 \\ =25-10 \\ =15 \end{gathered}`

Profit more earned by seeling 15 items than 5 items

`\begin{gathered} =P(15)-P(5) \\ =665-15 \\ =650 \end{gathered}`