-5 + 2 . | x + 3 | = -3
$⇒2.|x+3|=-3+5$
$⇒2.|x+3|=2$
$⇒|x+3|=1$
$⇒\left[ \begin{array}{l}x+3=1\\x+3=-1\end{array} \right.$
$⇒\left[ \begin{array}{l}x=1-3\\x=-1-3\end{array} \right.$
$⇒\left[ \begin{array}{l}x=-2\\x=-4\end{array} \right.$
Vậy $x∈${$-2;-4$}