Question

  

Answer 1

a: \(M=\dfrac{2\sqrt{x}-2}{\sqrt{x}-1}-\dfrac{3\sqrt{x}}{\sqrt{x}+1}\)

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

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

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

b: Khi x=25 thì \(M=\dfrac{-\sqrt{25}+2}{\sqrt{25}+1}=\dfrac{-5+2}{5+1}=\dfrac{-3}{6}=-\dfrac{1}{2}\)