ĐKXĐ: \(x\ge-4\)
\(\Leftrightarrow\sqrt{x+8}+2=\sqrt{5x+20}\)
\(\Leftrightarrow x+12+4\sqrt{x+8}=5x+20\)
\(\Leftrightarrow\sqrt{x+8}=x+2\left(x\ge-2\right)\)
\(\Leftrightarrow x+8=x^2+4x+4\)
\(\Leftrightarrow x^2+3x-4=0\Rightarrow\left[{}\begin{matrix}x=1\\x=-4\left(ktm\right)\end{matrix}\right.\)