What is the range of the function f(x)=12-3x for the domain {-4,-2,0,2,4}?

Anyone know? will mark brainliest if you're correct!

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.

Find the equation using the point (4,8)