Answer:
(x + 2)²
Step-by-step explanation:
x² + 4x + 4 ← is a perfect square of the form
(x + a)² = x² + 2ax + a²
Comparing coefficients of like terms
4 = 2² ⇒ a = 2 and 2ax = (2 × 2)x = 4x
Hence
x² + 4x + 4 = (x + 2)²
