Giải thích các bước giải:
$G=(\dfrac{\sqrt{x}-2}{x-1}-\dfrac{\sqrt{x}+2}{x+2\sqrt{x}+1}).\dfrac{x^2-2x+1}{2}$
$\to G=(\dfrac{\sqrt{x}-2}{(\sqrt{x}-1)(\sqrt{x}+1)}-\dfrac{\sqrt{x}+2}{(\sqrt{x}+1)^2}).\dfrac{(x-1)^2}{2}$
$\to G=\dfrac{(\sqrt{x}-2)(\sqrt{x}+1)-(\sqrt{x}+2)(\sqrt{x}-1)}{(\sqrt{x}-1)(\sqrt{x}+1)^2}.\dfrac{(x-1)^2}{2}$
$\to G=\dfrac{-2\sqrt{x}}{(\sqrt{x}-1)(\sqrt{x}+1)^2}.\dfrac{(\sqrt{x}-1)^2(\sqrt{x}+1)^2}{2}$
$\to G=\dfrac{-2\sqrt{x}(\sqrt{x}-1)}{2}$
