How do you find your revenue and profit doing equations?

Profit is different from revenue since you need to invest your money (called 'cost') to manufacture goods or services. So, a simple equation for 'revenue':

Profit = Revenue - Cost.

Lets say you are the basketball manufacturer who sells one ball for 30 dollars. And if you sell 100 balls, your revenue will be 3,000 dollars. However, to make 100 balls, it may be required to pay about 1,000 dollars for labors, rentals, machines, leathers, distributions, etc. So, your profit will be 2,000 dollars (3,000 revenue - 1,000 cost).