What is the factored expression

Acircle has a diameter will endpoints of (-2,8) and (6, 4). what is the center of the circle

In the geometric progression –3, 12, −48… what term is 3,072?

Consider a cube that has sides of length l. now consider putting the largest sphere you can inside this cube without any point on the sphere lying outside of the cube. the volume ratio -volume of the sphere/ volume of the cube is 1. 5.2 × 10−1 2. 3.8 × 10−1 3. 1.9 4. 2.5 × 10−1 5. 3.8