Factor. x2 + 6x + 9
(x + 6)2
(x – 3)2
(x – 6)2
(x + 3)2

The answer is D. 

I hope this helps. :) 

I'm sure of that answer! 

For (x + 6)2 you would add six a second time which is 12 then 12 times 2 is 24

For (x - 3)2 is 3 times 2 is 6 then subtract 3 is 3

For (x - 6)2 is 2 times 6 is 12 then subtract 6 which is 6

For (x + 3)2 you would do 3 times 2 is six then add three more is 9

QUICK NOTE IM REALLY SORRY IF THIS IS WRONG IM BAD AT MATH PLEASE DONT BE MAD