Question

Greatest common factor of 8a and 18a

Answer 1

8a = 2 * 2 * 2 * a
18a = 2 * 3 * 3 * a


2 and a are common factors, therefore the GCM of 8a and 18a is 2a.

Answer 2

ignore the a and add it at the end, because we know that both 8a and 18a are divisible by a
factors of 8:
1
8
4
2
factors of 18:
1
18
2
9
3
6
the highest number that both of them have in common is 2, so the GCF of 8a and 18a is 2a