ĐKXĐ: ...
\(\Leftrightarrow\left(\frac{5x-x^2}{x+1}\right)\left(\frac{x^2+5}{x+1}\right)=6\)
\(\Leftrightarrow\left(\frac{5x+5-\left(x^2+5\right)}{x+1}\right)\left(\frac{x^2+5}{x+1}\right)=6\)
\(\Leftrightarrow\left(5-\frac{x^2+5}{x+1}\right)\left(\frac{x^2+5}{x+1}\right)=6\)
Đặt \(\frac{x^2+5}{x+1}=t\Rightarrow\left(5-t\right)t=6\)
\(\Leftrightarrow t^2-5t+6=0\Rightarrow\left[{}\begin{matrix}t=2\\t=3\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}\frac{x^2+5}{x+1}=2\\\frac{x^2+5}{x+1}=3\end{matrix}\right.\) \(\Rightarrow\left[{}\begin{matrix}x^2+5=2x+2\\x^2+5=3x+3\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x^2-2x+3=0\\x^2-3x+2=0\end{matrix}\right.\) \(\Leftrightarrow...\)
