What is x?

3-2x=21

Show the steps?

Determine the volume of a cylinder bucket if the diameter is 8.5 in. and the height is 11.5 in.

If m 17 27 90 63 ** picture is attached

When solving this problem: 3025/5.5 = a/90.75 you get 49912.5 which would be the length of one of the sides of a square when the area is only 90.75 inches. is that answer correct, why, and how is it possible?