\(\Leftrightarrow\left(x^2-2x+1\right)+\left(y^2+4y+4\right)+\left(z^2-6z+9\right)-8=0\\ \Leftrightarrow\left(x-1\right)^2+\left(y+2\right)^2+\left(z-3\right)^2=8=0^2+2^2+2^2\)
Với \(\left\{{}\begin{matrix}x-1=0\\y+2=2\\z-3=2\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=1\\y=0\\z=5\end{matrix}\right.\)
Với \(\left\{{}\begin{matrix}x-1=2\\y+2=0\\z-3=2\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=3\\y=-2\\z=5\end{matrix}\right.\)
Với \(\left\{{}\begin{matrix}x-1=2\\y+2=2\\z-3=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=3\\y=0\\z=3\end{matrix}\right.\)
Vậy pt có nghiệm \(\left(x;y;z\right)=\left\{\left(1;0;5\right);\left(3;-2;5\right);\left(3;0;3\right)\right\}\)
