Đề mình thấy sao sao ý
[tex]Q=\frac{\sqrt{x-\sqrt{4(x-1)}}+\sqrt{x+\sqrt{4(x-1)}}}{\sqrt{x^2-\sqrt{4(x-1)}}}.(1-\frac{1}{x-1})\\=\frac{(\sqrt{x-1}-2)+\sqrt{x-1}+2}{\sqrt{x^2-\sqrt{4(x-1)}}}.\frac{x-2}{x-1}\\=\frac{2(x-2)}{\sqrt{x^2-\sqrt{4(x-1)}}(\sqrt{x-1})}[/tex]