Answer:
3a
Explanation:
First, cancel the 3 at the bottom by getting rid of it and changing the 9 to a 3. You can do this because 3 is one third of 9.
With the division property of exponents, you have to subtract 3-2 and you can leave a to the power of 1 on the numerator.
Then, cancel the b's out by getting rid of them.
You will be left with 3a.