Answer:
6
Step-by-step explanation:
The middle number is 12 and the last number is 36.
Factoring means we want something like
(d+_)(d+_)
Which numbers go in the blanks?
We need two numbers that...
Add together to get 12
Multiply together to get 36
with 6 and 6 to get...
(d+6)(d+6) or [tex](d+6) ^{2}[/tex]
