ĐKXĐ : \(x\ge\sqrt{2}-1\)
P/t \(\Leftrightarrow x+2\sqrt{x}-1=4\)
\(\Leftrightarrow x+2\sqrt{x}-5=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=-1+\sqrt{6}\left(tm\right)\\x=-1-\sqrt{6}\left(L\right)\end{matrix}\right.\)
Vậy ...
Sửa đề: \(\sqrt{x^2+2\sqrt{x-1}}=2\)
\(\Leftrightarrow\left|\sqrt{x-1}+1\right|=2\)
=>căn(x-1)+1=2
=>căn(x-1)=1
=>x-1=1
hay x=2