![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/step1.JPG\")
Method 1:
\Factor the each monomial.
\12x = 2 · 2 · 3 · x.
\40x2 = 2 · 2 · 2 · 5 · x · x.
\The GCF is the product of the common prime factors in each monomial.
\GCF = 2 · 2 · x = 4x
\The greatest common factor of 12x and 40x2 is 4x.![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/solution.JPG\")
The greatest common factor of 12x and 40x2 is 4x.