The gcf is not computing on this question
Answer provided by our tutors
You need to enter at least 2 expressions or 2 numbes to get GCF, you have entered only "21x+9xy-12xy^2".
If you want to find GCF for 21x,9xy and 12xy^2 you need to type in GCF (21x, 9xy, 12xy^2) and you will get the following result:
GCF (21x, 9xy, 12xy^2) = 3x