If there are 3 feet in 1 yard, how many yards are 54 feet?

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.

Can someone me out here number 4 plz

Identify the number as a rational or irrational.explain. 127