I need to know how to do number 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.

Which table represents a linear function? i'll give brainliest to first answer ^'^

Find the area of the region that is inside r=3cos(theta) and outside r=2-cos(theta). sketch the curves.