x^2 + 4x + 4 is a perfect square trinomial that can be factored as (x + 2)^2.
Step-by-step explanation:
To complete the expression x^2 + 4x + __ as a perfect square trinomial, we can take half of the coefficient of x (which is 4), square it, and then add it to the expression.
Half of 4 is 2, and 2 squared is 4, so we can add 4 to the expression to get:
x^2 + 4x + 4
This expression is a perfect square trinomial and can be factored as:
(x + 2)^2