The greatest common factor is exactly as it sounds: the greatest factors of two or more expressions.
Factorize the numbers and identify all common factors. To get the GCF multiply all common factors:
\(8m=2\cdot 2\cdot 2\cdot m,\\36m^3=2\cdot 2\cdot 3\cdot 3\cdot m\cdot m\cdot m,\\ 12=2\cdot 2\cdot 3\).
Common factors are: 2 and 2, their product is 2·2=4, then the greatest common factor is 4.
