P = \(\left[\dfrac{\left(\sqrt{x}-1\right)^2}{\left(\sqrt{x}+1\right)\left(\sqrt{x}-1\right)}-\dfrac{\left(\sqrt{x}+1\right)^2}{\left(\sqrt{x}+1\right)\left(\sqrt{x}-1\right)}\right]\cdot\left(\dfrac{x}{\sqrt{x}}-\dfrac{1}{\sqrt{x}}\right)\)
P = \(\dfrac{x-2\sqrt{x}+1-x-2\sqrt{x}-1}{x-1}\cdot\dfrac{x-1}{\sqrt{x}}\)
P = \(\dfrac{-4\sqrt{x}}{\sqrt{x}}\)
P = \(-4\)