So Sánh
\(\frac{2007}{2008}+\frac{2008}{2009}\)và \(\frac{2007}{2008}+\frac{2008}{2009}\)
so sánh 2008 với tổng 2009 số hạng sau\(s=\frac{2008+2007}{2009+2008}+\frac{^{2008^2+2007^2}}{2009^2+2008^2}+.....+\frac{2008^{2009}+2007^{2009}}{2009^{2009}+2008^{2009}}\)
So sánh : \(A=\frac{2006}{2007}+\frac{2007}{2008}+\frac{2008}{2009}+\frac{2009}{2006}\)với 4
ta có: \(A=\frac{2006}{2007}+\frac{2007}{2008}+\frac{2008}{2009}+\frac{2009}{2006}\)
A = \(1-\frac{1}{2007}+1-\frac{1}{2008}+1-\frac{1}{2009}+1+\frac{3}{2006}\)
A= \(4\)\(+\frac{3}{2006}-\left(\frac{1}{2007}+\frac{1}{2008}+\frac{1}{2009}\right)\)
Do 1/2007 < 1/2006 ; 1/2008<1/2006 ; 1/2009<1/2006=> 1/2007 + 1/2008 + 1/2009 < 1/2006 + 1/2006 + 1/2006
Mà 1/2006 + 1/2006 + 1/2006 = 3/2006
=> 3/2006 -( 1/2007 + 1/2008 + 1/2009) > 0
=> \(4+\frac{3}{2006}-\left(\frac{1}{2007}+\frac{1}{2008}+\frac{1}{2009}\right)>4\)
=> A > 4
Ta có:\(\frac{2006}{2007}< 1\)
\(\frac{2007}{2008}< 1\)
\(\frac{2008}{2009}< 1\)
\(\frac{2009}{2006}>1\)\(\frac{2006}{2007}+\frac{2007}{2008}+\frac{2008}{2009}+\frac{2009}{2006}< 4\)
Mk chưa thấy ai làm bài sai như thế đấy lỗi đó thì hs lớp 4 cũng phát hiện ra
So sánh:
\(A=\frac{2006}{2007}+\frac{2007}{2008}+\frac{2008}{2009}+\frac{2009}{2006}\)với 4
Hãy so sánh\(^{\frac{2007}{2008}+\frac{2008}{2009}+\frac{2010}{2011}+\frac{2011}{2008}}\)và 4
Ta có:4=1+1+1+1=\(\frac{2009}{2009}+\frac{2010}{2010}+\frac{2011}{2011}+\frac{2008}{2008}\)
\(\frac{2008}{2009}+\frac{1}{2009}+\frac{2009}{2010}+\frac{1}{2010}+\frac{2010}{2011}+\frac{1}{2011}+\frac{2008}{2008}\)
Xét \(A=\frac{2008}{2009}+\frac{2009}{2010}+\frac{2010}{2011}+\frac{2011}{2008}\)
\(=\frac{2009}{2009}+\frac{2010}{2010}+\frac{2011}{2011}+\frac{2008}{2008}+\frac{1}{2008}+\frac{1}{2008}+\frac{1}{2008}\)
xét \(\frac{1}{2009}< \frac{1}{2008};\frac{1}{2010}< \frac{1}{2008};\frac{1}{2011}< \frac{1}{2008}\)
\(\Rightarrow4< A\)
bạn chắc chắn là đúng chứ
Bạn chắc chắn là bạn làm đúng chứ? Với lại bạn đã từng làm bài này chưa?
So sánh A và B biết \(A=\frac{2006}{2007}-\frac{2007}{2008}+\frac{2008}{2009}-\frac{2009}{2010};B=\frac{1}{2006.2007}-\frac{1}{2008.2009}\)
So sánh :
B) \(\frac{2006}{2007}+\frac{2007}{2008}+\frac{2008}{2009}+\frac{2009}{2006}vs4\)
Nhưng mình cần lời giải chi tiết nhé 🤔
So sánh cặp số sau:
\(A=\frac{2006^{2007}+1}{2007^{2008}+1};B=\frac{2007^{2008}+1}{2008^{2009}+1}\)
Giúp!!!
A=\(\frac{2007^{2007}}{2008^{2008}}\)
B=\(\frac{2008^{2008}}{2009^{2009}}\)
Không dùng máy tính hãy so sánh : \(A=\frac{2006}{2007}+\frac{2007}{2008}+\frac{2008}{2009}+\frac{2009}{2006}\) với 4
Vì 2006/2007 ; 2007/2008 ; 2008/2009 ; 2009/2010 đều bé hơn 1 nên:
2006/2007 + 2007/2008 + 2008/2009 + 2009/2010 < 1 + 1 + 1 + 1 = 4.
Vậy ...
A=\(\frac{2006}{2007}+\frac{2007}{2008}+\frac{2008}{2009}+\frac{2009}{2006}\)=3-(\(\frac{1}{2007}+\frac{1}{2008}+\frac{1}{2009}\))+1+\(\frac{3}{2006}\)=4+(\(\frac{1}{2006}-\frac{1}{2007}\))+(\(\frac{1}{2006}-\frac{1}{2008}+\frac{1}{2009}\))
=> A>4 (\(\frac{1}{2006}>\frac{1}{2007}>\frac{1}{2008}>\frac{1}{2009}\))
tính nhanh : \(\frac{2007}{2008}\times\frac{1}{2009}+\frac{2007}{2008}:\frac{2009}{2008}+\frac{1}{2008}\)
2007/2008 x 1/2009 + 2007/2008 : 2009/2008 + 1/2008
= 2007/2008 x 1/2009 + 2007/2008 x 2008/2009 + 1/2008
= 2007/2008 x (1/2009 + 2008/2009) + 1/2008
= 2007/2008 x 1 + 1/2008
= 2007/2008 + 1/2008
= 2008/2008 = 1