=\(limn.\left(\sqrt{n^2+2n}-\left(n+1\right)\right)+limn\left(2n+1-2\sqrt{n^2+n}\right)\)
=\(lim\frac{-n}{\sqrt{n^2+2n}+n+1}+lim\frac{n}{2n+1+2\sqrt{n^2+n}}\)
=\(lim\frac{-1}{\sqrt{1+\frac{2}{n}}+1+\frac{1}{n}}+lim\frac{1}{2+\frac{1}{n}+2\sqrt{1+\frac{1}{n}}}=\frac{-1}{4}\)