Lời giải:
\(A=\sqrt{2017}-\sqrt{2016}=\frac{2017-2016}{\sqrt{2017}+\sqrt{2016}}=\frac{1}{\sqrt{2017}+\sqrt{2016}}\)
\(B=\sqrt{2018}-\sqrt{2017}=\frac{2018-2017}{\sqrt{2018}+\sqrt{2017}}=\frac{1}{\sqrt{2018}+\sqrt{2017}}\)
Dễ thấy \(0< \sqrt{2017}+\sqrt{2016}< \sqrt{2018}+\sqrt{2017}\Rightarrow \frac{1}{\sqrt{2017}+\sqrt{2016}}>\frac{1}{\sqrt{2018}+\sqrt{2017}}\)\(\Rightarrow A>B\)