Method 1:
\Factor the each monomial.
\12m2n3 = 2 · 2 · 3 · m · m · n · n· n
\70m3n = 2 · 5 · 7 · m · m · m · n
\The GCF is the product of the common prime factors in each monomial.
\GCF = 2 · m · m · n
\The greatest common factor of 12m2n3 and 70m3n is 2m2n.
The greatest common factor of 12m2n3 and 70m3n is 2m2n.
\