![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/step1.JPG\")
Method 1:
\Factor the each monomial.
\25a = 5 · 5 · a
\30b = 2 · 3 · 5 · b
\The GCF is the product of the common prime factors in each monomial.
\GCF = 5
\ The greatest common factor of 25a and 30b is 5.![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/solution.JPG\")
The greatest common factor of 25a and 30b is 5.