I just need help with the following question

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 expression is equivalent to 3^3 + 2^2?

In the geometric progression –3, 12, −48… what term is 3,072?