Answer
$$x^2 + 6x + 9$$
Work Step by Step
First, we expand the expression to clearly see all the terms:
$$(x + 3)(x + 3)$$
Then we use the FOIL method to multiply the two binomials together. In the FOIL method, we first multiply the first terms, then the outside terms, then the inside terms, and, finally, the last terms:
$$(x)(x) + (x)(3) + (3)(x) + (3)(3)$$
Let's multiply to simplify the expression:
$$x^2 + 3x + 3x + 9$$
Combine like terms:
$$x^2 + 6x + 9$$