Who likes Cadbury Cream Eggs ???

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.

Divide. reduce the answer to lowest terms.5 2/3 ÷ 3 1/9

Icould really use some with this question.