Solving a Multi-Step Equation

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.

The angle of a triangle are given as 6x,(x-3), and (3x+7). find x then find the measures of the angles

Can someone check if i did this right since i really want to make sure it’s correct. if you do you so much