Question

M=\(\left(\dfrac{\sqrt{a}+1}{\sqrt{ab}+1}+\dfrac{\sqrt{ab}+\sqrt{a}}{1-\sqrt{ab}}+1\right)\div\left(1-\dfrac{\sqrt{ab}+\sqrt{a}}{\sqrt{ab}-1}-\dfrac{\sqrt{a}+1}{\sqrt{ab}+1}\right)\) với a≥0; b≥0; ab≠1.

a)Rút gọn M.

b)Cho\(\dfrac{1}{\sqrt{a}}+\dfrac{1}{\sqrt{b}}=6\). Tìm GTLN M.