You can put this solution on YOUR website!
Revenue = Quantity*Price
Price = 2.50 + 0.0001(45000-Q) Q <= 45000
There are several ways to solve this. If you understand calculus, take the first derivative and solve for the max.
If you want to just use simple algebra, find the two places where the Revenue is 0 and then split the difference.
If you are good with parabolas, find the vertex.
whichever way, you find the most revenue selling 35,000 dogs