HELP PLEASE ANSWER THE THREE QUESTIONS IN FULLL 50 POINTS

Which is the correct first step in finding the area of the base of a cylinder with a volume of 26x cubic meters and a height of 6.5 meters? v=bh 6.5=b(26x) v=bh v=26pi+(6.5) v=bh v=26pi(6.5) v=bh 26pi=b(6.5)

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

Ineed with 8,9 and 10 love ya guysss