Does a trapezoid have obtuse angles

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.

Linda loans her friend $250 with a 5% monthly intrest rate. how much was the whole loan?

If there are 3.281 feet in 1 meter, how many inches are in one centimeter