50 POINTS I'll mark you brainliest just please respond ASAP

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

Graph of quadratic function f of x having x intercepts at ordered pairs negative 0, 0 and 10, 0. The vertex is at 5, 160.

Part A: What is an approximate average rate of change of the graph from x = 2 to x = 5, and what does this rate represent? (3 points)

Part B: Describe the constraints of the domain. (3 points)