#### Answer

$x=\{−6,2\}$

#### Work Step by Step

The left side of the given equation, $x^2+4x+4=16$, is a perfect square trinomial whose factored form is
$(x+2)^2=16$.
Taking the square root of both sides (the Square Root Property), the solutions to the given equation are
$x+2=\pm\sqrt {16}$
$x+2=\pm\sqrt {(4)2}$
$x+2=\pm4$
$x=−2+4$ or $x=-2-4$
$x=2$ or $x=-6$
Hence, $x=\{−6,2\}$.