What is the GCF for 12y and 28xy?

..12y = 2^2 * 3 ..........* y
28xy = 2^2 .....* 7 * x * y
--------------------------------------------
...........2^2 ...............* y
........= 4y

4y

it's 4y because if you look, both monomials have a y and the GCF between 12 and 28 are 4.

b) 4y

4y