Answer
$$(x + 11)^2$$
Work Step by Step
We can see that this polynomial fits the perfect square trinomial given by the following formula:
$$A^2 + 2AB + B^2 = (A + B)^2$$
We first figure out the $A$ and $B$ terms. In this problem, the $A$ term is $x$ and the $B$ term is the positive square root of $121$ or $11$. We now plug these values into the formula:
$$(A + B)^2 = (x + 11)^2$$
