Question

Answer 1

giúp mình với

 

Answer 2

\(=\left[{}\begin{matrix}1-x+3-x\left(x< 1\right)\\x-1+3-x\left(1\le x< 3\right)\\x-1+x-3\left(x\ge3\right)\end{matrix}\right.\\ =\left[{}\begin{matrix}4-2x\left(x< 1\right)\\2\left(1\le x< 3\right)\\2x-4\left(x\ge3\right)\end{matrix}\right.\)

Answer 3

TH1
\(1\le x\le3\)
=> x-1-x+3=2
TH2
\(x\le1\)
=>-x+1-x+3=-2x+4
TH3
\(x\ge3\)
=>x-1+x-3=2x-4