Calculating the Unit Price, Profit Functions from the Given Data

"A nationwide manufacture of calculators finds that its profits are $4 million when it sells 300,000 units. If the company’s fixed costs are $800,000 and unit variable costs are $20 per calculator, find a. The unit price of each calculator. b. The profit P(x) as a function of x, the number of calculators sold. c. The break‐even point. "