First see which ones can be added together. There is an “a” in 3a and 9a, so you can add them together. It wouldn’t make sense to add the “2” with them because it doesn’t have the variable in it, haha!
2 + (3a + 9a)
2 + 12a
I don’t know if you are asking to simplify it fully, but just in case, here it us:
Think about it, can you simplify any further? The answer is yes! Is there any common factor in 2 and 12? It’s 2! Since it’s the common factor, we can divide 2 + 12a by 2 to get it even more simplified.
2 + 12a/2
1 + 6a is the answer! Let me know if you have any more questions or if I got it wrong. Have a great day!