The area of a rectangle is 72 square meters. The length is 9 meters. What is
the width?

Consider the diagram. which line segment has the same measure as st? rx tx sr xs

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.

What is the missing step in this proof ?