a) P = \(\left(-\dfrac{\sqrt{x}\left(1+\sqrt{x}\right)}{\left(1+\sqrt{x}\right)\left(1-\sqrt{x}\right)}-\dfrac{\sqrt{x}\left(1-\sqrt{x}\right)}{\left(1+\sqrt{x}\right)\left(1-\sqrt{x}\right)}\right):\dfrac{2x\sqrt{x}}{1-x}\)
P = \(\left(\dfrac{-x-\sqrt{x}}{1-x}-\dfrac{\sqrt{x}-x}{1-x}\right).\dfrac{1-x}{2x\sqrt{x}}\)
P = \(\dfrac{-\sqrt{x}-x-\sqrt{x}+x}{1-x}\). \(\dfrac{1-x}{2x\sqrt{x}}\)
P = \(\dfrac{-2\sqrt{x}\left(1-x\right)}{2x\sqrt{x}\left(1-x\right)}\); P = \(\dfrac{-1}{x}\)
b) \(x=\sqrt{2^2+2.2.\sqrt{3}+\sqrt{3^2}}\)
\(=\sqrt{\left(2+\sqrt{3}\right)^2}\)
\(=2+\sqrt{3}\)
\(\Rightarrow P=\dfrac{-1}{2+\sqrt{3}}\)
