riddle question " max profit + units " 1. The problem statement, all variables and given/known data There is no demand for a new brand of mobile phones if the price is 20 $ or more. For each drop of 1 $ in the price, the demand increases by 500 units.The cost of producing x units is (12x + 2000)$. How many phones should be produced and sold to obtain a maximum profit? What is the price per unit charged to get maximum profit? 3. The attempt at a solution well to know the units i should use x=-b/2a and the max $ from y=c-(b^2/4a) but can someone tell me how to make the equation for this question ,,, P=R-C ,,, C=(12x + 2000) ,,, how to find R ?