(\(\dfrac{\sqrt{a}}{1-\sqrt{a}}\)+ \(\dfrac{\sqrt{a}}{1+\sqrt{a}}\)) : \(\dfrac{2\sqrt{a}}{a-1}\)= -1
VT= \(\dfrac{\sqrt{a}\left(1+\sqrt{a}\right)+\sqrt{a}\left(1-\sqrt{a}\right)}{1-a}\): \(\dfrac{2\sqrt{a}}{a-1}\)
= \(\dfrac{\sqrt{a}+a+\sqrt{a}-a}{1-a}\). \(\dfrac{a-1}{2\sqrt{a}}\)
= \(\dfrac{-2\sqrt{a}}{a-1}\). \(\dfrac{a-1}{2\sqrt{a}}\)= -1 =VP (đpcm)