Question 207560
First, list the prime factorization of each monomial. 



48cd: 2*2*2*2*3*c*d



{{{104c^4d}}}: 2*2*2*13*c*c*c*c*d



Now highlight the factors that the two expressions share in common



48cd: <font color="red">2*2*2</font>*2*3*<font color="red">c*d</font>



{{{104c^4d}}}: <font color="red">2*2*2</font>*13*c*c*c*<font color="red">c*d</font>



Now pick one set of these highlighted values and multiply


2*2*2*c*d=8cd


So the GCF of {{{48cd}}} and {{{104c^4d}}} is {{{8cd}}}