the answer is cube root of 6π2V over 2π. I just want to know how the answer is that.
3 Answers

V=4/3π r^3
r^3 = 3/4*V/π
r= Qubic root of [3/4 * V/π].
P.S. I don't understand your answer; 6pi2V over 2pi would be the same as 6V and that isn't right. It could be right if you had some extra information about r in the terms of V or something similar. I just don't know.Sorry!

V = 4/3 TT r^3 , taking TT for Pi since I couldn't write it
Divide both side by 4/3: 'Anything' divided by a number of the form a/b where b is different from 0, is the same as 'Anything' multiplied by b/a, wherever a is different from 0. So then V divided by 4/3 = 3/4 V.... right? And similar division of the equation on the right gets rid of the 4/3.
3/4 V = TT r^3 ... now divide both sides by pi and you will have
3/41/TTV = 3V/4TT = r^3.... then take the cube root of both sides. The one on the right becomes r. Therefore,
r = (3V/4TT)^1/3 .... Remember when a number is raised to any number 1/a (where a is different from 0), it is the same as computing the ath root of that number. So raising 3V/4TT to 1/3 means the cube root of 3V/4TT. So your answer is:
r = (3V/4TT)^1/3

Volume of a sphere= 4/3piradius^3
To solve for "r" you need to know the volume
To find the volume you need to know what r is.