(1 point) A 15 ft. ladder leans against a wall. The bottom of the ladder slides away from the wall at a rate of Ift./sec.. How fast is ladder sliding down the wall when the base of the ladder is 6 ft. away from the wall? ft./sec.. Round your answer to three decimal places.(1 point) Oil spilled from a ruptured tanker spreads in a circle whose area increases at a constant rate of 7 mizlhr. How rapidly is radius of the spill increasing when the area is 4 Ini2? The radius is increasing at ll === mi/hr. Round to three decimal places. (1 point) A boat is pulled into a dock by means of a rope attached to a pulley on the deck. The rope is attached to the front of the boat, which is 7 feet below the level of the pulley. If the rope is pulled through the pulley at a rate of 20 ft/min, at what rate will the boat be approaching the dock when 120 ft of rope is out? The boat will be approaching the dock at E! ft/min. (Round to three decimal places.) (1 point) Consider x3 + 5xy2 = -916, find dy dx when x = 4, y = -7 and = 2. dt dt dy dt Round to three decimal places.(1 point) Oil spilled from a ruptured tanker spreads in a circle whose area increases at a constant rate of 7 mil/hr. How rapidly is radius of the spill increasing when the area is 4 mil? The radius is increasing at :=: mi/hr. Round to three decimal places