Answer:
1/2
Step-by-step explanation:
The radius is 1/2 of the diameter
Answer:
They used 3.14 for pi:


Step-by-step explanation:
is the volume of a sphere with radius r.
I think that is the diameter given in the picture.
The radius is half the diameter.
So the radius is 5 since the diameter is 10.
Plug in this gives you:

4(3+x)
This is because 4*3=12 and 4*x is 4x so you get 12+4x which is the original equation