Question

find the greatest common factor (gcf). 45 and 9

Explanation:

Step1: List factors of 45

$1, 3, 5, 9, 15, 45$

Step2: List factors of 9

$1, 3, 9$

Step3: Identify common factors

$1, 3, 9$

Step4: Select the largest common factor

The maximum value in $\{1, 3, 9\}$ is 9.

Answer:

9