\(\dfrac{3\sqrt{x}-x-4}{x\sqrt{x}+1}-\dfrac{\sqrt{x}-1}{x-\sqrt{x}+1}+\dfrac{2}{\sqrt{x}+1}\left(dkxd:x\ge0\right)\)\(=\dfrac{3\sqrt{x}-x-4}{\left(\sqrt{x}+1\right)\left(x-\sqrt{x}+1\right)}-\dfrac{\sqrt{x}+1}{x-\sqrt{x}+1}+\dfrac{2}{\sqrt{x}+1}\)\(=\dfrac{3\sqrt{x}-x-4-\left(x-1\right)+2\left(x-\sqrt{x}+1\right)}{\left(\sqrt{x}+1\right)\left(x-\sqrt{x}+1\right)}\)\(=\dfrac{3\sqrt{x}-x-4-x+1+2x-2\sqrt{x}+2}{\left(\sqrt{x}+1\right)\left(x-\sqrt{x}+1\right)}\)\(=\dfrac{\sqrt{x}-1}{\left(\sqrt{x}+1\right)\left(x-\sqrt{x}+1\right)}\)\(=\dfrac{\sqrt{x}-1}{x\sqrt{x}+1}\)Câu trả lời: \(\dfrac{3\sqrt{x}-x-4}{x\sqrt{x}+1}-\dfrac{\sqrt{x}-1}{x-\sqrt{x}+1}+\dfrac{2}{\sqrt{x}+1}\left(dkxd:x\ge0\right)\)\(=\dfrac{3\sqrt{x}-x-4}{\left(\sqrt{x}+1\right)\left(x-\sqrt{x}+1\right)}-\dfrac{\sqrt{x}+1}{x-\sqrt{x}+1}+\dfrac{2}{\sqrt{x}+1}\)\(=\dfrac{3\sqrt{x}-x-4-\left(x-1\right)+2\left(x-\sqrt{x}+1\right)}{\left(\sqrt{x}+1\right)\left(x-\sqrt{x}+1\right)}\)\(=\dfrac{3\sqrt{x}-x-4-x+1+2x-2\sqrt{x}+2}{\left(\sqrt{x}+1\right)\left(x-\sqrt{x}+1\right)}\)\(=\dfrac{\sqrt{x}-1}{\left(\sqrt{x}+1\right)\left(x-\sqrt{x}+1\right)}\)\(=\dfrac{\sqrt{x}-1}{x\sqrt{x}+1}\)