The distance of d across the square

What is the answer to |-2x-5|-|-4+8| and x=7

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.

Either enter an exact answer in terms of \piπ or use 3.143.14 for \piπ and enter your answer as a decimal.