Can someone help me understand this?

Use the radius you found in part i (r=26.8 cm) with the surface area formula below to find the surface area of the sphere. show your work and round your answer to the nearest tenth. the surface area of a sphere: sa = 4πr^2 self note: 3.8.4

The circle below is centered at the point (3, 1) and has a radius of length 2. what is the equation?

Suppose the equation ||x-a|-b|=2008 has 3 distinct real roots and a not =0. find the value of b.