\(a)P = \dfrac{{x + 2}}{{x\sqrt x - 1}} + \dfrac{{\sqrt x + 1}}{{x + \sqrt x + 1}} - \dfrac{1}{{\sqrt x - 1}}\\ P = \dfrac{{x + 2 + \left( {\sqrt x - 1} \right)\left( {\sqrt x + 1} \right) - 2\left( {x + \sqrt x + 1} \right)}}{{\left( {\sqrt x - 1} \right)\left( {x + \sqrt x + 1} \right)}}\\ P = \dfrac{{ - 1 - 2\sqrt x }}{{\left( {\sqrt x - 1} \right)\left( {x + \sqrt x + 1} \right)}}\\ P = \dfrac{{ - 1 - 2\sqrt x }}{{x\sqrt x - 1}} \)