Answer:
36
Step-by-step explanation:
You take 1/2 the linear term's coefficient and square it.
The linear term is the term that contains just an x and a number -- in this case 12x
Take 1/2 12 = 6
and square it
6^2 = 36
So when you've done that you should get
x^2 + 12x + 36 = 11 + 36
x^2 + 12x + 36 = 47
