Question

The greatest common factor of 15u2v3, 20u5v2, and 45u3v5???

Answer 1

Do you mean:
\[15u ^{2}v ^{3}, 20u ^{5}v ^{2}, 45u ^{3}v ^{5}\]

Answer 2

yes

Answer 3

Ok. The greatest common factor for the coefficients is 5, since all of them are divisible by 5. For the variables, you just want to find the power than can be pulled out of all of the given terms.
So for u:
\[u ^{2}\]
For v:
\[v ^{2}\]
Then multiply them together and you have your GCF:
\[5u ^{2}v ^{2}\]