How do you find the real or imaginary solutions of a polynomial equation

Aball is thrown from a height of 139 feet with an initial downward velocity of 15 ft/s. the ball's height h (in feet) after t seconds is given by the following. h=139-15t-16t^2 how long after the ball is thrown does it hit the ground? round your answer(s) to the nearest hundredth. (if there is more than one answer, use the "or" button.) t =

Find the volume of the solid bounded by the plane z=0 and the paraboloid z=1-x^2 –y^2

Find a conversion factor between square centimeters and square meters. write it in three forms. square centimeters = 1 square meter