A=2001^3+2002^3+2004^3+2005^3+2006^3+2007^3+2008^3+2009^3
tính chính xác...
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
20013 + 20023 + 20033 + 20043 + 20053 + 20063 + 20073 + 20083 + 20093 = \(\sum\limits^{2009}_{2001}x^3\) = 72541712030
![](https://rs.olm.vn/images/avt/0.png?1311)
\(A=\frac{2002}{2001}+\frac{2003}{2002}+\frac{2004}{2003}+\frac{2005}{2004}+\frac{2006}{2005}+\frac{2007}{2006}+\frac{2008}{2007}+\frac{2009}{2008}>\frac{2001}{2001}+\frac{2002}{2002}+\frac{2003}{2003}+\frac{2004}{2004}+\frac{2005}{2005}+\frac{2006}{2006}+\frac{2007}{2007}+\frac{2008}{2008}\)
\(A=\frac{2002}{2001}+\frac{2003}{2002}+\frac{2004}{2003}+\frac{2005}{2004}+\frac{2006}{2005}+\frac{2007}{2006}+\frac{2008}{2007}+\frac{2009}{2008}>1+1+1+1+1+1+1+1\)\(A=\frac{2002}{2001}+\frac{2003}{2002}+\frac{2004}{2003}+\frac{2005}{2004}+\frac{2006}{2005}+\frac{2007}{2006}+\frac{2008}{2007}+\frac{2009}{2008}>8\)
\(A>8\)
![](https://rs.olm.vn/images/avt/0.png?1311)
A = 20013 + 20023 + 20033 + 20043 + 20053 + 20063 + 20073 + 20083 + 20093
= ( 2001 + 2002 + 2003 + 2004 + 2005 + 2006 + 2007 + 2008 + 2009 )3
= ( ( 2001 + 2009 ) + ( 2002 + 2008 ) + ( 2003 + 2007 ) + ( 2004 + 2006 ) + 2005 )3
= ( 4010 + 4010 + 4010 + 4010 + 2005 ) 3
= ( 4010 . 4 + 2005 )3
= ( 16040 + 2005 )3
= 180453