How do you use prime factorizationto find the gcf of two numbers?

Answer:
Example: 30 and 42
2 x 3 x 5 = 30
2 x 3 x 7 = 42
Select the common factors.
2 x 3 = 6, the GCF

First answer by ID1246253806. Last edit by Ericbarnes. Contributor trust: 140 [recommend contributor recommended]. Question popularity: 0 [recommend question].