Match each pair of monomials with their greatest common factor.

I will answer these in the order they are given from the left to the right on the top.

1.  4p^3q^2
2.  8pq^5
3.  4p^2q^5
4.  8p^2q
5.  4p^2q  (This one is not listed, but this is the greatest common factoring).

The way you do this is find the greatest common factor of the coefficients (front number) and
 
Look at variables that match and choose the smallest exponent as part of your gcf (this is how many times they match in both lists, making it a factor of both).