a = 2002.2002 = 2002 . (2000+2) = 2002.2000 + 2002.2
b = 2000.2004 = 2000 . (2002+2) = 2000.2002 + 2000.2
Vậy a>b.
a > b nhé vì :
a = 2002.2002 = 2002 .( 2002 + 2 ) = 2002.2000 + 2002.2
b = 2000.2004 = 2000 .(2002 + 2 ) = 2000.2002 + 2000.2
nên a > b
Ta có :
a = 2002 . 2002 = ( 2001 + 1 ) . ( 2004 - 2 )
= ( 2001 + 1 ) . 2004 - 2 . ( 2001 + 1 )
= 2001 . 2004 + 2004 - 2 . 2001 - 2
= 2001 . 2004 + ( 2004 - 2 . 2001 - 2 )
= 2001 . 2004 - 2000 < 2001 . 2004
=> a < b
Vậy a < b