-f(3)
Function for algebra

Suppose that the price p (in dollars) and the weekly sales x (in thousands of units) of a certain commodity satisfy the demand equation 4p cubedplusx squaredequals38 comma 400. determine the rate at which sales are changing at a time when xequals80, pequals20, and the price is falling at the rate of $.20 per week.

Which of the following is the result of expanding

Which of the following would be a good name for the function that takes the weight of a box and returns the energy needed to lift it?