`#Sad`
`c)`
`x/(\sqrt{x}-1) = 2\sqrt{x}`
`\text{ĐK:}` `{(x>=0),(x \ne 1):}`
`x/(\sqrt{x}-1) = 2\sqrt{x}`
`⇔ 2\sqrt{x}. (\sqrt{x}-1) = x`
`⇔ 2x-2\sqrt{x} = x`
`⇔ x-2\sqrt{x} = 0`
`⇔ x = 2\sqrt{x}`
`⇔ x^2 = 4x`
`⇔ x^2-4x = 0`
`⇔ x(x-4) = 0`
`⇔` \(\left[ \begin{array}{l}x=0\\x-4=0\end{array} \right.\)
`⇔` \(\left[ \begin{array}{l}x=0\\x=4\end{array} \right.\) `\text{(thỏa mãn)}`
`\text{Vậy}` `x=0` `\text{hoặc}` `x=4`
