Step-by-step explanation:
The GCF is the greatest common factor. A factor is a number being multiplied.
36 can be multiplied by 1,2,3,4,6,9,12,18,and 36, of course.
63 can be multiplied by 1,3,7,9,21, and 63.
We are looking for the largest number that 36 and 63 have in common.
It's not 1 or 3. The only other number they have in common is 9.
Hope it helps!
