what is the greatest common factor of 12a and 9a²?\n9\n36\n3a\n12a²

Explanation:

Step1: Factorize 12a

$12a = 2\times2\times3\times a$

Step2: Factorize 9a²

$9a^{2}=3\times3\times a\times a$

Step3: Find common factors

The common factors are 3 and a.

Step4: Calculate GCF

The GCF is $3\times a=3a$.

Answer:

C. 3a