Question

what is the greatest common factor of 27, 9, and 45?

Explanation:

Step1: Prime - factorize the numbers

$27 = 3\times3\times3$; $9 = 3\times3$; $45=3\times3\times5$

Step2: Identify common factors

The common factors are two 3s.

Step3: Calculate GCF

$3\times3 = 9$

Answer:

9