2: \(=lim\left(\dfrac{4n^2+2n+1-4n^2}{\sqrt{4n^2+2n+1}+2n}+2020\right)\)
\(=lim\left(\dfrac{2n+1}{\sqrt{4n^2+2n+1}+2n}+2020\right)\)
\(=lim\left(\dfrac{2+\dfrac{1}{n}}{\sqrt{4+\dfrac{2}{n}+\dfrac{1}{n^2}}+2}+2020\right)\)
\(=\dfrac{2}{2+2}+2020=\dfrac{2}{4}+2020=2020.5\)