\(\dfrac{\sqrt{x}+3}{x-4}-\dfrac{\sqrt{x}}{x+2\sqrt{x}}-\dfrac{1}{\sqrt{x}-2}\)
\(=\dfrac{\sqrt{x}+3}{\left(\sqrt{x}-2\right)\left(\sqrt{x}+2\right)}-\dfrac{1}{\sqrt{x}+2}-\dfrac{1}{\sqrt{x}-2}\)
\(=\dfrac{\sqrt{x}+3-\sqrt{x}+2-\sqrt{x}-2}{\left(\sqrt{x}-2\right)\cdot\left(\sqrt{x}+2\right)}\)
\(=\dfrac{-\sqrt{x}+3}{x-4}\)