Please help me im very depressed and im struggling a lot on my math and i really need some answers Which number sentence is true?

What is the volume of the sphere shown below with a radius of 3?

Explain step-by-step how to simplify -5(2x – 3y + 6z – 10).

Set $r$ is a set of rectangles such that (1) only the grid points shown here are used as vertices, (2) all sides are vertical or horizontal and (3) no two rectangles in the set are congruent. if $r$ contains the maximum possible number of rectangles given these conditions, what fraction of the rectangles in set $r$ are squares? express your answer as a common fraction.