Đề : Trục căn thức ở mẫu
f) \(\dfrac{2}{\sqrt{6}-\sqrt{5}}\) l) \(\dfrac{3}{\sqrt{10}+\sqrt{7}}\) m) \(\dfrac{1}{\sqrt{x}-\sqrt{y}}\) ( x>0 ,y>0,\(x\ne y\) )
o) \(\dfrac{2ab}{\sqrt{a}-\sqrt{b}}\) (\(a\ge0,b\ge0,a\ne b\))
P) \(\dfrac{P}{2\sqrt{P}-1}\) (\(P\ge0\) , \(P\ne\dfrac{1}{4}\))