`|x + 1| × 2 = 4`
`|x + 1| = 4 ÷ 2`
`|x + 1| = 2`
`⇒` \(\left[ \begin{array}{l}x+1=2\\x+1=-2\end{array} \right.\)
`⇒` \(\left[ \begin{array}{l}x=2 - 1\\x=-2 - 1\end{array} \right.\)
`⇒` \(\left[ \begin{array}{l}x=1\\x=-3\end{array} \right.\)
Xin hay nhất !
