Answer:
Step-by-step explanation:
1) List the factors of each number.
Factors of 6 : 1, 2, 3, 6
Factors of 42 : 1, 2, 3, 6, 7, 14, 21, 42
Factors of 18 : 1, 2, 3, 6, 9, 18
2) Find the largest number that is shared by all rows above. This is the GCF.
GCF = 6
