A = \(\frac{2009.2010-2}{2008+2008.2010}=\frac{2009.2010-2}{2008.\left(2010+1\right)}=\frac{2009.2010-2}{2008.2011}=\frac{2008.2010+2010-2}{2008.2011}=\frac{2008.2011}{2008.2011}=1\)
B = \(\frac{-2009.20102010}{20092009.2010}=\frac{-2009.10001.2010}{2009.10001.2010}=-1\)
1 > -1 => A > B
Ta có:
\(A=\frac{2009.2010-2}{2008+2008.2010}\)
\(A=\frac{\left(2008+1\right).2010-2}{2008+2008.2010}\)
\(A=\frac{2008.2010+2010-2}{2008+2008.2010}\)
\(A=\frac{2008.2010+2008}{2008+2008.2010}\)
\(A=1\)
\(B=\frac{-2009.20102010}{20092009.2010}\)
\(B=\frac{-2009.2010.10001}{2009.10001.2010}\)
\(B=-1\)
Vì \(1>-1\Rightarrow A>B\)
Vậy \(A>B\)
Ta có -2009.20102010 bé hơn 0 =>B bé hơn 0 (1)
Lại có:2009.2010-2lonws hơn 0=> A lớn hơn 0 (2)
Từ (1) và (2) => A>B
