Answer:

Step-by-step explanation:
Assuming the problem is asking you to factor out the formula, it can be done easily by finding a common number with the two givens. 
4 goes into both 12 and 16 evenly, so we will use this to factor. But that's not all, we have the n-variable to worry about. 
Look at the n-variable exponents in the problem, take the highest power that can go be subtracted from both and use that. We have a  and
 and  . Since 5 can't go into 3, we must use 3 to factor.
. Since 5 can't go into 3, we must use 3 to factor. 
Our factoring variable will therefore be  . Now, use this to simply divide and get the answer:
. Now, use this to simply divide and get the answer:

So how did we get this? For the whole numbers, we have to divide: (12/4, 16/4). Next, we have to minus the exponents since we are dividing. 
When dividing the 12 and 4, minus the  and
 and  to get
 to get  . Get rid of the
. Get rid of the  term for the 16 and leave the 4. And there's your answer!
 term for the 16 and leave the 4. And there's your answer!