4047991- 2010 . 2009 / 4050000 - 2011 . 2009
=9901/9901
=1
4047991- 2010 . 2009 / 4050000 - 2011 . 2009
=9901/9901
=1
tính nhanh A= 4047991- 2010 x 2009/ 4050000-2011 x 2009
so sánh A và B với A=2008/2009 +2009/2010 +2010/2011 và B= (2008+2009+2010) / (2009+2010+2011)
so sánh A và B với A=2008/2009 +2009/2010 +2010/2011 và B= 2008+2009+2010 / 2009+2010+2011
so sanh
A=2008/2009+2009/2010+2010+2011
B=2008+2009+2010/2009+2010+2011
So sánh : \(A=\frac{2008}{2009}+\frac{2009}{2010}+\frac{2010}{2011}vàB=\frac{2008+2009+2010}{2009+2010+2011}\)
Bài 2 : So sánh
A=2008/2009+2009+2010+2010+2011 và B=2008+20092+2010/2009+2010+2011
tinh nhanh B=1/1+2009/2011+2009/2010 + 1/1+2010/2009+2010/2011 + 1/1+2011/2009+2011/2010
Bài 2 : So sánh
\(A=\dfrac{2008}{2009}+\dfrac{2009}{2010}+\dfrac{2010}{2011}vàB=\dfrac{2008+2009+2010}{2009+2010+2011}\)
a) Chứng tỏ rằng: 1/41+1/42+1/43+...+1/80 > 7/12
b) So sánh: A=2008/2009+2009/2010+2010/2011 VÀ B=2008+2009+2010/2009+2010+2011