Can someone help me out here? Not sure how to solve this problem or where to start either?

What is (28 + 7 + 6 + 3) x 1/2 show your work

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.

Elizabeth is using a sample to study american alligators. she plots the lengths of their tails against their total lengths to find the relationship between the two attributes. which point is an outlier in this data set?