ĐKXĐ: x>=-3
\(\sqrt{x+3}+\sqrt{3x+9}=x+3\)
=>\(\sqrt{x+3}+\sqrt{3}\cdot\sqrt{x+3}=x+3\)
=>\(\sqrt{x+3}\left(\sqrt{x+3}-1-\sqrt{3}\right)=0\)
=>\(\left[{}\begin{matrix}x+3=0\\\sqrt{x+3}=\sqrt{3}+1\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-3\left(nhận\right)\\x+3=4+2\sqrt{3}\end{matrix}\right.\)
=>\(\left[{}\begin{matrix}x=-3\left(nhận\right)\\x=2\sqrt{3}+1\left(nhận\right)\end{matrix}\right.\)
ĐKXĐ: \(x\ge-3\)
\(\sqrt{x+3}+\sqrt{3x+9}=x+3\)
\(\Leftrightarrow\sqrt{x+3}+\sqrt{3}.\sqrt{x+3}=x+3\)
\(\Leftrightarrow\left(\sqrt{3}+1\right)\sqrt{x+3}=x+3\)
\(\Leftrightarrow\left(4+2\sqrt{3}\right)\left(x+3\right)=\left(x+3\right)^2\)
\(\Rightarrow\left[{}\begin{matrix}x+3=0\\x+3=4+2\sqrt{3}\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=-3\\x=1+2\sqrt{3}\end{matrix}\right.\)
