Solution: Problem 1: Using the five-step method and the univariate optimization model (1), the code names of all variables are put forward: the cost per vehicle c; Sales volume before discount n; Sales volume after discount; The price of each car before discount p; The price of each car after discount; Sales before discount r; Sales after discount; Profit before discounting l; Discounted profit' l; The profit before discount is 1500. When the discount is X, CPnL has the highest profit. At this time, it is assumed that the activity is completed at one time, that is, the manufacturer reduces x 100 USD at one time and increases x% 15 sales volume to maximize profits. (2) Choose the modeling method: So can we get the equations from the known conditions in the problem? )' ('')15.01('1500100' cpnlxnncpxpp (3) deduces the model formula, Discounted profit function can be derived from the relationships:) 100 1500) (6500) (4) Solution model: It is known that the discounted profit function of the manufacturer is:)1000xndxdl25x (5) Answer the question: In general, no matter what the value of n is, the manufacturer