Question

rút gọn dùm em vs ạ

Answer 1

Với `x >= 0,x \ne 4` có:

   `1/[\sqrt{x}+2]+\sqrt{x}/[2-\sqrt{x}]+[2x-\sqrt{x}+2]/[x-4]`

`=[\sqrt{x}-2-\sqrt{x}(\sqrt{x}+2)+2x-\sqrt{x}+2]/[(\sqrt{x}-2)(\sqrt{x}+2)]`

`=[\sqrt{x}-2-x-2\sqrt{x}+2x-\sqrt{x}+2]/[(\sqrt{x}-2)(\sqrt{x}+2)]`

`=[x-2\sqrt{x}]/[(\sqrt{x}-2)(\sqrt{x}+2)]`

`=[\sqrt{x}(\sqrt{x}-2)]/[(\sqrt{x}-2)(\sqrt{x}+2)]=\sqrt{x}/[\sqrt{x}+2]`