\(=\left(\dfrac{x+9}{x-9}-\dfrac{\sqrt{x}\left(\sqrt{x}-3\right)}{x-9}\right).\dfrac{x-3\sqrt{x}}{\sqrt{x}}\\ =\left(\dfrac{x+9-x+3\sqrt{x}}{x-9}\right).\dfrac{x-3\sqrt{x}}{\sqrt{x}}\\ =\dfrac{3\left(3+\sqrt{x}\right)}{\left(\sqrt{x}-3\right)\left(3+\sqrt{x}\right)}.\dfrac{\sqrt{x}\left(\sqrt{x}-3\right)}{\sqrt{x}}\\ =3\)