###### Example6.3.17

An artist sells his paintings at $\(200.00\) per piece. 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 $\(20.00\) of price increase per painting, his customers would buy \(5\) fewer paintings annually.

Assume the artist would raise the price of his painting \(x\) times, each time by $\(20.00\text{.}\) Use an expanded polynomial to represent his new income per year.