Ta có: \(5A=\dfrac{5^{2011}+5}{5^{2011}+1}=1+\dfrac{4}{5^{2011}+1}\)
\(5B=\dfrac{5^{2010}+5}{5^{2010}+1}=1+\dfrac{4}{5^{2010}+1}\)
\(\dfrac{4}{5^{2011}+1}< \dfrac{4}{5^{2010}+1}\Rightarrow1+\dfrac{4}{5^{2011}+1}< 1+\dfrac{4}{5^{2010}+1}\)
\(\Rightarrow5A< 5B\Rightarrow A< B\)
Vậy A < B
nhân 2010 với A và B rút gọn là xong