###### Example 6.4.19

Tyrone is an artist and he sells each of his paintings for \(\$200\text{.}\) Currently, he can sell \(100\) paintings per year. Thus, his annual income from paintings is \(200\cdot100=20000\) dollars. He plans to raise the price. However, for each $\(20\) price increase per painting, his customers would buy \(5\) fewer paintings annually.

Assume Tyrone would raise the price of his paintings \(x\) times, each time by $\(20\text{.}\) Use an expanded polynomial to represent his new income per year.