ĐKXĐ: \(x\ge4\)
\(\Leftrightarrow\sqrt{5x-1}\ge\sqrt{x-1}+\sqrt{x-4}\)
\(\Leftrightarrow5x-1\ge2x-5+2\sqrt{x^2-5x+4}\)
\(\Leftrightarrow3x+4\ge2\sqrt{x^2-5x+4}\)
\(\Leftrightarrow\left(3x+4\right)^2\ge4\left(x^2-5x+4\right)\)
\(\Leftrightarrow5x^2+44x\ge0\Rightarrow x\ge4\)