Question

rút gọn: \(A=\)\(\dfrac{-2}{\sqrt{x}-2}\)\(-\dfrac{\sqrt{x}}{\sqrt{x}+2}\)

Answer 1

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

\(=\dfrac{-2\left(\sqrt{x}+2\right)-\sqrt{x}\left(\sqrt{x}-2\right)}{\left(\sqrt{x}-2\right)\left(\sqrt{x}+2\right)}\)

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

\(=\dfrac{-4-x}{x-4}\)

Answer 2

\(=\dfrac{-2\sqrt{x}-4-x+2\sqrt{x}}{x-4}=\dfrac{-x-4}{x-4}\)