\(\dfrac{2004.2007+6}{2005.2005+2009}\)
= \(\dfrac{4022028+6}{4020025+2009}\)
= \(\dfrac{4022034}{4022034}\)
= 1
Xét tử số :
2004 . 2007 + 6
= (2005 - 1) . 2007 + 6
= 2005 . 2007 - 2007 + 6
= 2005 . (2005 + 2) - 2007 + 6
= 2005 . 2005 + 2005 . 2 - 2007 + 6
= 2005 . 2005 + 4010 - 2007 + 6
= 2005 . 2005 + 2009
=>2004.2007+6/2005.2005+2009 =1
Xét tử số :
2004 . 2007 + 6
= (2005 - 1) . 2007 + 6
= 2005 . 2007 - 2007 + 6
= 2005 . (2005 + 2) - 2007 + 6
= 2005 . 2005 + 2005 . 2 - 2007 + 6
= 2005 . 2005 + 4010 - 2007 + 6
= 2005 . 2005 + 2009
=>2004.2007+6/2005.2005+2009 =1
2004 . 2007 + 6
= (2005 - 1) . 2007 + 6
= 2005 . 2007 - 2007 + 6
= 2005 . (2005 + 2) - 2007 + 6
= 2005 . 2005 + 2005 . 2 - 2007 + 6
= 2005 . 2005 + 4010 - 2007 + 6
= 2005 . 2005 + 2009
=>2004.2007+6/2005.2005+2009 =1