Revenue is the total amount of income generated by the sale of goods.
Let assume we sold x number of widgets. Revenue will the price of each widget and number of widgets. p(x) is the price demand function.
R(x) = x(30-x)
R(10) = 10 (30-10) = 200
So, after selling 10 widgets, total amount of income generated by the sale of goods is 200 dollars.
P(x) = R(x) - C(x)
Profit function tells you how much profit did u made which can be calculated from by subtracting the cost of making products from revenue.
P(10) = R(10) - C(10)
P(10) = 200 - (5*10 +20)
P(10) = 200 - 70 = 130
So, the profit by selling 10 widgets is 130 dollars.
I hope this helps.
Gary M.
Thank you!09/08/20