Answer: 9
Step-by-step explanation:
The factors of 18: 1, 2, 3, 6, 9, 18
The factors of 27: 1, 3, 9, 27
Factors of 18: 1, 2, 3, 6, 9, 18 .
Factors of 27: 1, 3, 9, 27 .
Common factors of 18 and 27: 1, 3, 9 .
Greatest common factor: 9 .
