Answer
$x^{2}$ + 4x + 4 = (x + 2)(x + 2)
Answer = 2
$\rightarrow$(x + 2)
Work Step by Step
$x^{2}$ + 4x + 4 = (x + 2)(x + 2)
We need two numbers such that their product is 4 and sum is also 4.
But, one number is already given: $\rightarrow$ 2
Thus, the other number is $\frac{4}{2}$ = 2.
Since 2 + 2 = 4
and 2(2) = 4,
2 is the reqiured number $\rightarrow$ (x + 2).