\(ĐK:\left\{{}\begin{matrix}x\ge1\\y\ge-3\\z\ge-4\end{matrix}\right.\\ PT\Leftrightarrow\left(x-1-4\sqrt{x-1}+4\right)+\left(y+3-2\sqrt{y+3}+1\right)+\left(z+4-6\sqrt{z+4}+9\right)=0\\ \Leftrightarrow\left(\sqrt{x-1}-2\right)^2+\left(\sqrt{y+3}-1\right)^2+\left(\sqrt{z+4}-3\right)^2=0\\ \Leftrightarrow\left\{{}\begin{matrix}\sqrt{x-1}=2\\\sqrt{y+3}=1\\\sqrt{z+4}=3\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x-1=4\\y+3=1\\z+4=9\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=5\left(tm\right)\\y=-2\left(tm\right)\\z=5\left(tm\right)\end{matrix}\right.\)
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