TH1 : x<1
\(\Rightarrow x-1+x-3=6\\ \Rightarrow2x-4=6\\ \Rightarrow2x=10\\ \Rightarrow x=5\left(loai\right)\)
TH2: \(1\le x\le3\)
\(\Rightarrow x-1-\left(x-3\right)=6\\ \Rightarrow0x+2=6\\ \Rightarrow0x=4\\ \Rightarrow x\in\varnothing\)
TH3:\(x>3\)
\(\left(x-1\right)+\left(x-3\right)=6\\ \Rightarrow2x-4=6\Rightarrow x=5\left(TM\right)\)
Vậy x=5