Ta có B = 2013 . 2013
=> B = 2013.(2014 - 1)
=> B = 2013 . 2014 - 2013
=> B = (2012+1).2014 - 2013
=> B = 2012.2014 + 2014 - 2013
=> B = 2012.2014 + 1 > 2012.2014 = A
Vậy A<B
Dễ thui
Ta có: A = 2014 x 2012
B = 2013 x 2013
=> A < B
Ta có B = 2013 . 2013
=> B = 2013.(2014 - 1)
=> B = 2013 . 2014 - 2013
=> B = (2012+1).2014 - 2013
=> B = 2012.2014 + 2014 - 2013
=> B = 2012.2014 + 1 > 2012.2014 = A
Vậy A<B
Ta có B = 2013 . 2013
=> B = 2013.(2014 - 1)
=> B = 2013 . 2014 - 2013
=> B = (2012+1).2014 - 2013
=> B = 2012.2014 + 2014 - 2013
=> B = 2012.2014 + 1 > 2012.2014 = A
Vậy A<B
A=2014x 2012 =***8
B=2013 x2013 =***9
(***=***)
=>A<B