Question

Answer 1

1: Thay x=9 vào A, ta được:

\(A=\frac{\sqrt9}{\sqrt9-2}=\frac{3}{3-2}=3\)

2: T=A-B

\(=\frac{\sqrt{x}}{\sqrt{x}-2}-\frac{2}{\sqrt{x}+2}-\frac{\sqrt{x}}{x-4}\)

\(=\frac{\sqrt{x}\left(\sqrt{x}+2\right)-2\left(\sqrt{x}-2\right)-\sqrt{x}}{\left(\sqrt{x}-2\right)\left(\sqrt{x}+2\right)}=\frac{x+2\sqrt{x}-2\sqrt{x}+4-\sqrt{x}}{\left(\sqrt{x}-2\right)\left(\sqrt{x}+2\right)}\)

\(=\frac{x-\sqrt{x}+4}{x-4}\)