a: Sửa đề: \(C=\left(\dfrac{2x+1}{\sqrt{x^3}+1}-\dfrac{\sqrt{x}}{x-\sqrt{x}+1}\right)\left(\dfrac{1-\sqrt{x^3}}{1+\sqrt{x^3}}-\sqrt{x}\right)\)
\(=\dfrac{2x+1-x-\sqrt{x}}{\left(\sqrt{x}+1\right)\left(x-\sqrt{x}+1\right)}\cdot\dfrac{1-x\sqrt{x}-\sqrt{x}-x^2}{1+x\sqrt{x}}\)
\(=\dfrac{1}{\sqrt{x}+1}\cdot\dfrac{\left(1-x\right)\left(1+x\right)-\sqrt{x}\left(1+x\right)}{\left(1+\sqrt{x}\right)\left(1-\sqrt{x}+x\right)}\)
\(=\dfrac{\left(1+x\right)\left(1-x-\sqrt{x}\right)}{\left(1+\sqrt{x}\right)^2\left(1+x-\sqrt{x}\right)}\)