Choose the equation below that represents the line that passes through the point (7,-2) and has a slope of -3.
Оа
y-2--3(x + 7)
Ob y+7-3(x - 2)
Oc y+ 2 --3x - 7)
Od y-7--3(x+2)

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.