A=2010+20102+20103+.....+20102010
A=2010(1+2010)+20103(1+2010)+........+20109(1+2010)
A=2010.2011+20103.2010+....+20109.2011
A=2011(2010+....+20109) chia hết cho 2011
=> A chia hết cho 2011(đpcm)
A = 2010 + 20102 + 20103 + ... + 20102010
A = 2010 . ( 1 + 2010 ) + 20103 . (1 + 2010 ) + ... + 20109 . ( 1 + 2010 )
A = 2010 . 2011 + 20103 . 2011 + ... + 20109 . 2011
A = 2011 . ( 2010 + 20103 + ... + 20109 )
Mà 2011 . ( 2010 + 20103 + ... + 20109 ) \(\in\)2011
=> A \(\in\)2011
๖²⁴ʱ𝒄𝒉𝒖́𝒄 𝒆𝒎 𝒉𝒐̣𝒄 𝒕𝒐̂́𝒕✟ᴾᴿᴼシ
Lộn ko phải \(\in\)mà là \(⋮\) nha
