Please help me ASAP or else I’m gonna panic please please

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.

If g^-1(x) is the inverse of g (x) which statement must be true

The cost of turkey is directly proportional to its weight. if a 12-pount turkey costs $27, how much does a 16-pound turkey cost? a. $33.75 b. $36.00 c. $31.00 d. $32.50