The common factors are: 1, 3
The common factors of 6, 21, and 39 are 1 and 3
factors of 63 =7*9 or 7*3*3 factors of 78=2*39, or 2*3*13 the GCF is 3
Common factors of 10 and 63 are: 1.
The common factors of 28 and 63 are: 1 and 7
The common factors of 30 and 63 are 1 and 3.
The common factors of 15 and 63 are: 1 and 3
The common factors of 63 and 91 are 1 and 7.
The common factors of 21 and 63 are 1, 3, 7, and 21
Since 13 is a factor of 39, all of its factors are common.
The common factors of 54 and 63 are: 1, 3, and 9
The common factors of 36 and 63 are 1, 3 and 9
The common factors of 63 and 56 are: 1, 7