so sanh :A=2013^2012+1/2013^2013+1 va 2013^2013+1/2013^2014+1
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Ta có: 1- 2012/2013=1/2013
1- 2013/2014=1/2014
Mà 1/2013>1/2014
vậy 2012/2013<2013/2014
a= (2000+ 14) . (2000+12)= 2000(14+12)= 2000. 168
b= 2000 . 169
vậy b>a
Ta có:
A=2012 x 2014
B = 2013 x 2013 = 2012 x 2014 + 1
Vậy B lớn hơn A
ta có: \(A=\frac{2014^{2013}+1}{2014^{2013}-1}=\frac{2014^{2013}-1+2}{2014^{2013}-1}=1+\frac{2}{2014^{2013}-1}\)
\(B=\frac{2014^{2013}-1}{2014^{2013}-3}=\frac{2014^{2013}-3+2}{2014^{2013}-3}=1+\frac{2}{2014^{2013}-3}\)
\(\Rightarrow\frac{2}{2014^{2013}-1}< \frac{2}{2014^{2013}-3}\)
\(\Rightarrow1+\frac{2}{2014^{2013}-1}< 1+\frac{2}{2014^{2013}-3}\)
=> A < B
\(\frac{2012}{2013}\)và \(\frac{2013}{2014}\)
=>\(\frac{2012}{2013}\) >\(\frac{2013}{2014}\) vì rút gọn\(\frac{2012}{2013}\frac{2013}{2014}=\frac{2012}{1}\frac{1}{2014}\)
=>\(\frac{4052168}{2014}>\frac{2014}{2014}\)
ĐÓ MÌNH LÀM XONG RỒI
\(A=\frac{2014^{2013}+1}{2014^{2014}+1}<\frac{2014^{2013}+1+2013}{2014^{2014}+1+2013}\)
\(=\frac{2014\left(2014^{2012}+1\right)}{2014\left(2014^{2013}+1\right)}\)
\(=\frac{2014^{2012}+1}{2014^{2013}+1}\)\(=B\)
=> A < B
\(\frac{2011.2013+2014}{2012.2012+2013}=\frac{2011.2013+2013+1}{2012.2012+2012+1}=\frac{2013.\left(2011+1\right)+1}{2012.\left(2012+1\right)+1}=\frac{2013.2012+1}{2012.2013+1}=1\)
Vậy \(\frac{2011.2013+2014}{2012.2012+2013}=1\)
(Dấu . là nhân nha bạn)
Đặt B = 2013^2013+1/2013^2014+1
Ta có: \(B=\frac{2013^{2013}+1}{2013^{2014}+1}< \frac{2013^{2013}+1+2012}{2013^{2014}+1+2012}=\frac{2013^{2013}+2013}{2013^{2014}+2013}=\frac{2013\left(2013^{2012}+1\right)}{2013\left(2013^{2013}+1\right)}=\frac{2013^{2012}+1}{2013^{2013}+1}=A\)
Vậy A > B