\(\dfrac{401}{200}=401:200=\left(400+1\right):200=2+\dfrac{1}{200}\)
\(\dfrac{399}{199}=399:199=\left(398+1\right):199=2+\dfrac{1}{199}\)
Vì \(\dfrac{1}{199}>\dfrac{1}{200}\) Nên \(2+\dfrac{1}{200}< 2+\dfrac{1}{199}\)=>\(\dfrac{399}{199}>\dfrac{401}{200}\)