\(\left|x+11\right|=8\\ \Leftrightarrow\left[{}\begin{matrix}x+11=8\\x+11=-8\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x=3\\x=-19\end{matrix}\right.\)
Vậy `x in {3;-19}`
` | x + 11| = 8`
\(\Rightarrow\left[{}\begin{matrix}x+11=8\\x+11=-8\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=8-11\\x=-8-11\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=-3\\x=-19\end{matrix}\right.\)
`|x + 11| = 8`
\(=>\left\{{}\begin{matrix}x+11=8\\x+11=-8\end{matrix}\right.\)
\(=>\left\{{}\begin{matrix}x=-3\\x=-19\end{matrix}\right.\)
`|x+11|=8`
`=>`$\left[\begin{matrix} x+11=8\\ x+11= -8\end{matrix}\right.$
`=>`$\left[\begin{matrix} x=-3 \\ x=-19\end{matrix}\right.$
Vậy `x` `in` `{−3;−19}`
`=> x + 11 = 8` hoặc `x + 11 = -8`
`=> x = -3` hoặc `x = -19`.