Please help!

If answered the correctly they will be marked as the brainliest

The graph below shows a company’s profit f(x) in dollars, depending on the price of erasers x, in dollars sold by the company

Part a: what do the x- intercepts and maximum value of the graph represent? What are the intervals where the function is increasing and decreasing and what do they represent about the sale and profit?

Part b. What is an approximate average rate of change of the graph from x=1 to x=4 and what does it represent?

Part c. Describe the constraints of the domain