Question 254558
Here was the problem:
Select the GCF of these numbers. 25 · 5· 11 and 23· 52 · 7
Lets rewrite each in prime factored form:
25 * 5 * 11 = 5^3 * 11
23 * 52 * 7 = 2^2 * 7 * 13 * 23
The GCF is the biggest stuff they share. 
They do not share any 2's
They do not share any 5's
They do not share any 7's
They do not share any 11's
They do not share any 13's
They do not share any 23's
So, the GCF in this case is 1.