The answer to this question is d
Answer:
Step-by-step explanation:
The volume of a sphere is

We are told our volume is 500pi/3, so we fill that in and solve for r:

Start by multiplying both sides by 3 over 4 pi:

Simplifying gives us

Take the cubed root of both sides to get that
r = 5
1. 7.5 because Y/75 X 10/100 = 750 /100 = 7.5
2. .75 because Y/75 X 1/100 = 75/100 = .75
Step-by-step explanation:
4x^2 - 20 = 5
4x^2 -25 = 0
4x^2 = 25
2x = 5, or -5
x = 5/2 , or -5/2