Rút gọn:

a) \(\frac{a-b}{\sqrt{a}-\sqrt{b}}\)-\(\frac{\sqrt{a^3}-\sqrt{b^3}}{a-b}\)(\(a\ge0\),\(b\ge0\),\(a\ne b\))

b)\(\frac{\left(\sqrt{a}-\sqrt{b}\right)^2-4\sqrt{ab}}{\sqrt{a}-\sqrt{b}}-\frac{a\sqrt{b}+b\sqrt{a}}{\sqrt{ab}}\)\(\left(a>0,b>0,a\ne b\right)\)

C)\(\left(\frac{1}{\sqrt{a}-1}-\frac{1}{\sqrt{a}}\right)\div\left(\frac{\sqrt{a}+1}{\sqrt{a}-2}-\frac{\sqrt{a}+2}{\sqrt{a}-1}\right)\)\(\left(a>0,a\ne1,a\ne4\right)\)

d)\(\left(\frac{a\sqrt{a}+b\sqrt{b}}{\sqrt{a}+\sqrt{b}}-\sqrt{ab}\right)\)\(\left(\frac{\sqrt{a}+\sqrt{b}}{a-b}\right)^2\)\(\left(a>0,b>0,a\ne b\right)\)

e)\(\left(\frac{\sqrt{x}}{3+\sqrt{x}}+\frac{x+9}{9-x}\right)\):\(\left(\frac{3\sqrt{x}+1}{x-3\sqrt{x}}-\frac{1}{\sqrt{x}}\right)\)\(\left(x>0,x\ne9\right)\)