解:?$ (1) ①$?當(dāng)?$x < -3$?時(shí),
原不等式變形為?$\begin {cases}x < -3 -(x + 3) > 5 + x\end {cases},$?
解得?$x < -4;$?
?$②$?當(dāng)?$x\geq -3$?時(shí),
原不等式變形為?$\begin {cases}x\geq -3 \\x + 3 > 5 + x\end {cases},$?
該不等式組無(wú)解。
綜合①②可得,原不等式的解集為?$x < -4。$?
?$(2) ①$?當(dāng)?$x\geq 3$?時(shí),
原不等式變形為?$\begin {cases}x\geq 3 \\x + x - 3 < 5\end {cases},$?
解得?$3\leq x < 4;$?
?$②$?當(dāng)?$x < 0$?時(shí),
原不等式變形為?$\begin {cases}x < 0 \\-x - x + 3 < 5\end {cases},$?
解得?$-1 < x < 0;$?
?$③$?當(dāng)?$0\leq x < 3$?時(shí),
原不等式變形為?$\begin {cases}0\leq x < 3\\x + 3 - x < 5\end {cases},$?
解得?$0\leq x < 3。$?
綜合①②③可得,原不等式的解集為
?$-1 < x < 4。$?