Can someone explain because my teacher has no time to teach me this and could use on the first three

Hello!

To answer these, you can use prime factorization! Here is the first one:

1) 16x² and 8

Well we know the GCF will not have any "x" since only one of the numbers do. So, here is the prime factorization for each, excluding the "x", and I have also bolded the common numbers between the two:

          16                    8

        2 · 8                 2 · 4

          2 · 4                  2 · 2

             2 · 2

Finally, multiply the common numbers (only once for each common number): 2 x 2 x 2= 8 is your GCF!!!

Hope this helps! :)

the answer is two. hope this !

9x