Question

Answer 1

a: \(M=\dfrac{x\sqrt{x}-3-2\left(x-6\sqrt{x}+9\right)-x-4\sqrt{x}-3}{\left(\sqrt{x}-3\right)\left(\sqrt{x}+1\right)}\)

\(=\dfrac{x\sqrt{x}-x-4\sqrt{x}-6-2x+12\sqrt{x}-18}{\left(\sqrt{x}-3\right)\left(\sqrt{x}+1\right)}\)

\(=\dfrac{x\sqrt{x}-3x+8\sqrt{x}-24}{\left(\sqrt{x}-3\right)\left(\sqrt{x}+1\right)}\)

\(=\dfrac{x+8}{\sqrt{x}+1}\)

b; Khi \(x=6-2\sqrt{5}\) thì \(M=\dfrac{6-2\sqrt{5}+8}{\sqrt{5}-1+1}=\dfrac{14-2\sqrt{5}}{\sqrt{5}}=\dfrac{14\sqrt{5}-20}{5}\)