Here we have to find the GCF of 60jk and 45jkm.
GCF means the greatest common factor. To find the greatest common factor first we have to find all factors of the monomials. Then we have to choose the common factors of them and multiplication of the common factors is the GCF of them.
So first we will have to find all factors of 60jk and 45jkm.
All factors of 60jk =

All factors of 45jkm =

Now the greatest common factor is the GCF.
The common factors between them are =

So here the required GCF =
=

=

So here the answer is = 15jk