# Thread: Determine the increase in sales

1. ## Determine the increase in sales

This is a practice problem in my book. I have the solution, 40, but I don't know how to find it. Help please.

A company will sell N unites of a product after spending $x thousand in advertising as given by N=60x-x² 5≤x≤30 Approximately what increase in sales will result by increasing the advertising budget from$10,000 to $11,000 Thanks for any help 2. First, realize that x is in thousands of dollars. Thus, evaluate N for$10,000 (i.e., x = 10) and for $11,000 (i.e., x = 11). Since the range of x is provided, which when translated says N works for advertising budgets of$5,000 to $30,000, these evaluations for N will work. What do you get for N in each case? Take their difference. I will add, my answer was 39, not 40. In other words, the company will sell 39 more units when the advertising spending is increased from$10,000 to \$11,000.