$|5 +x| = 5$
$⇒ \left[ \begin{array}{l}5 +x=5\\5 +x=-5\end{array} \right. ⇒ \left[ \begin{array}{l}x=0\\x=-10\end{array} \right.$
$Vậy$ $x ∈$ {$0; -10$}
$(5x -10)(3 +x) = 0$
$⇒ \left[ \begin{array}{l}5x -10=0\\3 +x=0\end{array} \right. ⇔ \left[ \begin{array}{l}x=2\\x=-3\end{array} \right.$
$Vậy$ $x ∈$ {$2; -3$}