Question

P=\(\left(\dfrac{\sqrt{x}}{\sqrt{x}-3}+\dfrac{\sqrt{x}}{\sqrt{x}+3}\right):\dfrac{\sqrt{4x}}{9-x}\)

Answer 1

\(P=\dfrac{x+3\sqrt{x}+x-3\sqrt{x}}{x-9}\cdot\dfrac{-\left(x-9\right)}{2\sqrt{x}}\)

\(=\dfrac{-2x}{2\sqrt{x}}=-\sqrt{x}\)

Answer 2

đk x≠ 9

\(P=\left(\dfrac{\sqrt{x}\left(\sqrt{x}+3\right)+\sqrt{x}\left(\sqrt{x}-3\right)}{x-9}\right).\dfrac{9-x}{\sqrt{4x}}\\ =\dfrac{x+3\sqrt{x}+x-3\sqrt{x}}{x-9}.\dfrac{-\left(x-9\right)}{2\sqrt{x}}\\ =\dfrac{2x}{1}.\dfrac{-1}{2\sqrt{x}}\\ =-\sqrt{x}\)