Question

so sánh hai phân số

\(\dfrac{2005}{2007}và\dfrac{2007}{2009}\)

Answer 1

Ta có : 

 

2005/2007=2007-2/2007=2007/2007 -2/2007=1 -2/2007

2007/2009 =2009-2007/2009=2009/2009 -2/2009=1-2009

vì 2007<2009 nên 2/2007>2/2009

⇒1-2/2007 <1-2/2009

⇒2005/2007 <2007/2009

Answer 2

Tham khảo nhé !

Ta có : \(\dfrac{2005}{2007}=2007-\dfrac{2}{2007}=\dfrac{2007}{2007}-\dfrac{2}{2007}=1-\dfrac{2}{2007}\)

\(\dfrac{2007}{2009}=2009-\dfrac{2007}{2009}=\dfrac{2009}{2009}-\dfrac{2}{2009}=1-2009\)

Vì \(2007<2009\) nên \(\dfrac{2}{2007}>\dfrac{2}{2009}\)

\(1-\dfrac{2}{2007}< 1-\dfrac{2}{2009}\)

\(\dfrac{2005}{2007}< \dfrac{2007}{2009}\)

Answer 3

2005/2007<2007/2009