\(\Leftrightarrow x^2+3x-1-\left(x+2\right)\sqrt{x^2+2}=0\)
Đặt \(\sqrt{x^2+2}=a>0\)
\(a^2-\left(x+2\right)a+3x-3=0\)
\(\Delta=\left(x+2\right)^2-4\left(3x-3\right)=x^2-8x+16=\left(x-4\right)^2\)
\(\Rightarrow\left[{}\begin{matrix}a=\frac{x+2+x-4}{2}=x-1\\a=\frac{x+2-x+4}{2}=3\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}\sqrt{x^2+2}=x-1\\\sqrt{x^2+2}=3\end{matrix}\right.\) \(\Rightarrow...\)