Xin hay nhất nhé tus^^
$\text{a)}$ $\frac{1002}{1004}$ $\text{và}$ $\frac{1001}{1002}$
$\text{Ta có:}$
$\text{1 - }$$\frac{1002}{1004}$ $\text{=}$ $\frac{2}{1004}$
$\text{1 - }$$\frac{1001}{1002}$ $\text{=}$ $\frac{1}{1002}$ $\text{=}$ $\frac{2}{2004}$
$\text{Vì }$$\frac{2}{1004}$ $\text{>}$ $\frac{2}{2004}$ $\text{hay}$ $\frac{2}{1004}$ $\text{>}$ $\frac{1}{1002}$ $\text{nên}$ $\frac{1002}{1004}$ $\text{<}$ $\frac{1001}{1002}$
$\text{Vậy}$ $\frac{1002}{1004}$ $\text{<}$ $\frac{1001}{1002}$
$\text{b) }$$\frac{2009}{2007}$ $\text{và}$ $\frac{2007}{2005}$
$\text{Ta có:}$
$\frac{2009}{2007}$ $\text{- 1 =}$ $\frac{2}{2007}$
$\frac{2007}{2005}$ $\text{- 1 =}$ $\frac{2}{2005}$
$\text{Vì}$ $\frac{2}{2007}$ $\text{<}$ $\frac{2}{2005}$ $\text{nên}$ $\frac{2009}{2007}$ $\text{<}$ $\frac{2007}{2005}$
$\text{Vậy}$ $\frac{2009}{2007}$ $\text{<}$ $\frac{2007}{2005}$
