Can anyone me with these three questions?

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.

Solve each equation using the quadratic formula. find the exact solutions. 6n^2 + 4n - 11

What would the rule be for the reflection of y=-3