How do you find the prime factors of two numbers?

Answer 1

Heres an example...

15 and 35

what goes into 15? what goes into 35

3 x 5 7x5

so the prime factors for 15 are 3 and 5 and 35 they are 7 and 5.

so the greatest common factor is 5.

and the prime factorization is 3x7x5^2(squared)

Answer 2

Use two factor trees.