Find the vertex of the following expression (x + 4)(x - 2) plz try to have the steps I need the credit

What aspects of lines have to be diffrent

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.

What is the radical expression that is equivalent to the expression 27 1 over 5?