Respuesta :
Answer:
3
Step-by-step explanation:
Step 1) list out all the factors
18: 1, 2, 3, 6, 9, 18
39: 1, 3, 13, 39
Step 2) find the greatest factor both numbers have (Greatest Common Factor)
18: 1, 2, 3, 6, 9, 18
39: 1, 3, 13, 39
Step 4) that number is your GCF
3