Please help me idk this

Iwant to know what 3g+5h+4g-2h is my teacher is too selfish to tell us

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.

Sasha drank 8 bottles of water everyday for a week. how many bottles of water did she drink in total?