List factors of 63: List the factors of 63.Factors of 63: 1, 3, 7, 9, 21, 63
List factors of 42: List the factors of 42.Factors of 42: 1, 2, 3, 6, 7, 14, 21, 42
Identify common factors of 63 and 42: Identify the common factors of 63 and 42.Common factors of 63 and 42: 1, 3, 7, 21
Find greatest common factor of 63 and 42: Find the greatest common factor (GCF) of 63 and 42.The greatest common factor is the largest number in the list of common factors.GCF of 63 and 42: 21