Answer:
7 and 14
28 and 7
Step-by-step explanation:
7 & 14's GCF is 7 since it's the largest factor for both of them.
21 & 3's GCF is 3 since it's the largest factor for both of them.
7 & 1's GCF is 1 since it's the largest factor for both of them.
28 & 7's GCF is 7 since it's the largest factor for both of them.
