They are 1 and 3
Factors of 20: 1, 2, 4, 5, 10, 20.Factors of 63: 1, 3, 7, 9, 21, 63.GCF (20, 63) = 1
20, 40, 60, 80, 100, 120, 140, 160, 180, 200 . . .
1 and 3 will go into both numbers evenly with no remainders
1,2,4,5,10,20 (the factors of 20)
7 and 9 are two numbers that go into 63.
1 and 3 can go into 12 and 63.
63
20, 21, 22 if you add them.
1, 3, 7, 9, 21, 63.
1, 3, 7, 9, 21, 63.
1, 3, 7, 9, 21 and 63.
1, 3, 7, 9, 21, 63.
1,3,7.9,21
1, 3, 7, 9, 21, 63.
The number 63 can be evenly divided by 1, 3, 7, 9, 21, and 63.
1 and 7.