Question

Answer 1

a: ĐKXĐ: x>=0; x<>1

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

\(=\dfrac{3x+5\sqrt{x}-2}{\left(\sqrt{x}+2\right)}\cdot\dfrac{\sqrt{x}+1}{1}\)

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

c: Khi x=4-2căn3 thì \(P=\left[3\left(\sqrt{3}-1\right)-2\right]\left[\sqrt{3}-1+1\right]\)

\(=\sqrt{3}\left(3\sqrt{3}-5\right)=9-5\sqrt{3}\)