`(x-1)=2x√(x+2)`
⇔`(x-1)^2=4x^2(x+2)`
⇔`x^2-2x+1=4x^3+8x^2`
⇔`4x^2+7x^2+2x-1=0`
⇔`4x^3+4x^2+3x^2+3x-x-1=0`
⇔`(4x^2+3x-1)(x+1)=0`
⇔`(4x^2+4x-x-1)(x+1)=0`
⇔`(4x-1)(x+1)^2=0`
⇔\(\left[ \begin{array}{l}4x-1=0\\x+1=0\end{array} \right.\)
⇔\(\left[ \begin{array}{l}x=\frac{1}{4}\\x=-1\end{array} \right.\)