TH1: \(x\le-1\)
\(pt\Leftrightarrow-x-1-3x+3=4-2x\)
\(\Leftrightarrow2x=-2\)
\(\Leftrightarrow x=-1\left(tm\right)\)
TH2: \(-1< x\le1\)
\(pt\Leftrightarrow x+1-3x+3=4-2x\)
\(\Leftrightarrow0x=0\)
\(\Rightarrow-1< x\le1\)
TH3: \(1< x\le2\)
\(pt\Leftrightarrow x+1+3x-3=4-2x\)
\(\Leftrightarrow6x=6\)
\(\Leftrightarrow x=1\left(l\right)\)
TH4: \(x>2\)
\(pt\Leftrightarrow x+1+3x-3=-4+2x\)
\(\Leftrightarrow2x=-2\)
\(\Leftrightarrow x=-1\left(l\right)\)
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