HELP MATH IS NOT MY SPECIALTY AND I NEED TO PASS

What expression is equivalent to 1/2(2+3x-6)

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 variable in a relation who’s value depends on the value of the independent variable is called what?