Answer:
18 is the GCF
Step-by-step explanation:
The factors of 36 are:
1, 2, 3, 4, 6, 9, 12, 18, and 36
The factors of 54 are:
1, 2, 3, 6, 9, 18, 27, and 54
The factors of 18 are:
1, 2, 3, 6, 9, and 18
All of the numbers have 18 as the greatest common factor.