( 98 x 7676 - 9898 x 76 ) : ( 2001 x 2002 x 2003 ...... 2010 )

= 0 : ( 2001 x 2002 x 2003 ..... 2010 )

= 0

(98x7676-9898x76):(2001x2002x2003....2010)

=0:(2001x2002x2003x...2010)

= 0

tính theo kiểu của các bạn là tính bình thường.

 Đặt (2001×2002×2003×...×2010) = A

= (98x101x76-9898x76): A

= (9898x76-9898x76):A

= 0:A

= 0

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(98×7676-9898×76):(2001×2002×2003)

=(98×76×101-98×101×76):(2001×2002×2003)

=0:(2001×2002×2003)

=0

2001/1999=1/2/1999

2007/2005=1/2/2005

 ta so sanh mau so hai phan so

cung tu mau lon hon thi be hon

vay:2001/1999>2007/2005

Giúp mình nha

Ta có: 1/ 2001 . 2003 = 1/2001 - 1/2003...

=> 1/2001 - 1/2003 + 1/2003 - 1/2005 + 1/2005 - 1/2007 + ... +1/2009 - 1/2011 +1/2011 - 1/2013

= 1/2001 - 1/2013

= 4/ 1342671

\(\frac{1}{2001\times2003}\)+\(\frac{1}{2003\times2005}\)+\(\frac{1}{2005\times2007}\)+........+\(\frac{1}{2009\times2011}\)+\(\frac{1}{2011\times2013}\)

=\(\frac{1}{2001}-\frac{1}{2003}+\frac{1}{2003}-\frac{1}{2005}+\frac{1}{2005}-\frac{1}{2007}\)+........+\(\frac{1}{2009}\)-\(\frac{1}{2011}+\frac{1}{2011}-\frac{1}{2013}\)

=\(\frac{1}{2001}\)-\(\frac{1}{2013}\)

=\(\frac{2013}{4028013}-\frac{2001}{4028013}\)=\(\frac{2}{4028013}\)

a,-136+123+(-264)+(-83)+240

= (123 - 83) - (136 + 264) + 240

= -40 - 400 + 240

= (240 - 40) - 400

= 200 - 400 = -200

b,-596+2001+1999+(-404)+189

= (2001 + 1999) - (596 + 404) + 189

= 4000 - 1000 + 189

= 3000 + 189

= 3189