The Greatest Common Factor (GCF) is very important when factoring. Later on, you will forget to pull out a GCF and the answer will be wrong. Always look for a GCF before doing anything.
Let's try factoring these:
a.)
The greatest common factor of this expression is 9, because it is the maximum number that both can go into. Let's solve.
This is the simplest this expression can get. This would be your final answer. Let's try the other one.
b.)
The GCF of this one is 12. Let's simplify it.
This is also the simplest you can get it. You can do nothing further. So, your final answers are:
a.)
b.)