$\sqrt{2x-1}-\sqrt{\dfrac{1}{2}x-2}=1$
$\Rightarrow 2x-1-2\sqrt{(2x-1)(0,5x-2)}+0,5x-2=1$
$\Rightarrow -2\sqrt{(2x-1)(0,5x-2)}=-2,5x+4$
$\Rightarrow \sqrt{x^2-4,5x+2}=1,25x-2$
$\Rightarrow x^2-4,5x+2=1,5625x^2-5x+4$
$\Rightarrow 0,5625x^2-0,5x+2=0$ (Vô nghiệm)
$\to S=\varnothing$
