To rewrite the polynomial \( x^2 + 4x + 4 \) using the polynomial identity \( x^2 + 2ax + a^2 = (x + a)(x + a) \), we need to identify \( 2a \) and \( a^2 \) in the expression.
In the given polynomial \( x^2 + 4x + 4 \):
- The coefficient of \( x \) is \( 4 \).
- The constant term is \( 4 \).
We can identify \( 2a \) and \( a^2 \) as follows:
- Since \( 2a = 4 \), we have \( a = 2 \).
- Since \( a^2 = 4 \), we can also verify that \( 2^2 = 4 \).
Applying the identity:
\[ x^2 + 4x + 4 = x^2 + 2(2)x + 2^2 = (x + 2)(x + 2) \]
Thus, we can write:
\[ x^2 + 4x + 4 = (x + 2)(x + 2) \]
Therefore, the correct response is:
\( x^2 + 4x + 4 = (x + 2)(x + 2) \).