Ta có :
\(1-\dfrac{2009}{2010}=\dfrac{1}{2010}\\ 1-\dfrac{2010}{2011}=\dfrac{1}{2011}\)
Mà \(\dfrac{1}{2010}>\dfrac{1}{2011}\) \(\Rightarrow\dfrac{2009}{2010}< \dfrac{2010}{201}\)
2009/2010>2010/2011
lấy 1 trừ cho các phân số rồi so sánh
chúc bạn học tốt!
ta có:
\(\dfrac{2009}{2010}=\dfrac{2009+1-1}{2010}\)
\(=\dfrac{\left(2009+1\right)-1}{2010}=1-\dfrac{1}{2010}\)
tương tự:
\(\dfrac{2010}{2011}=\dfrac{2010+1-1}{2011}=1-\dfrac{1}{2011}\)
so sánh: \(1-\dfrac{1}{2010}\)và\(1-\dfrac{1}{2011}\)
ta có: \(\dfrac{1}{2010}>\dfrac{1}{2011}\)
\(\Rightarrow1-\dfrac{1}{2010}< 1-\dfrac{1}{2011}\)
\(\Rightarrow\dfrac{2009}{2010}< \dfrac{2010}{2011}\)
