Suppse that the price p (in dollars) and the weekly sales x (in thousands of units) of a certain commodity satisfy the following demand equation. 3p3 + x2 = 24900 Determine the rate at which sales are changing at a time when x = 30, p = 20, and the price is falling at the rate of $1.5 per week. Rate of Change of Sales = thousands of units/week Note that the price is falling, what does this tell you about the sign of %