Answer:
The GCF is going to be 9
Step-by-step explanation:
When finding the GCF, you want to do prime factorization of each number.
18's prime factorization is, 2 × 3 × 3, which equals 18
36's prime factorization is 2 × 2 × 3 × 3, which equals 36
45's prime factorization is 5 × 3 × 3, which equals 45
Now all you have to do is find the factors common in each one, which is 2 three's. You then multiply 3 × 3 = 9. That is your answer
