={\frac{\sqrt{n}-\sqrt{n+2}}{{(}{\sqrt{n+2}+\sqrt{n+1}}{)}\cdot{{(}{\sqrt{n}+\sqrt{n+1}}{)}}}}\cdot{\frac{\sqrt{n}+\sqrt{n+2}}{\sqrt{n}+\sqrt{n+2}}}={\frac{-2}{{(}{\sqrt{n+2}+\sqrt{n+1}}{)}\cdot{(}{\sqrt{n}+\sqrt{n+2}}{)}\cdot{(}{\sqrt{n}+\sqrt{n+2}}{)}}}}