What is the answer to this question

Figure abcd is a parallelogram. if point c lies on the line x = 2, what is the y-value of point c

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.

Which equation results from adding the equations in this system? x+6y=9 and -x+2y=-15