\(\Leftrightarrow\sqrt{x+1}=5-2x\)
\(\Leftrightarrow\left\{{}\begin{matrix}5-2x\ge0\\x+1=\left(5-2x\right)^2\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}x\le\frac{5}{2}\\4x^2-21x+24=0\end{matrix}\right.\) \(\Rightarrow x=\frac{21-\sqrt{57}}{8}\)