a= (2000+ 14) . (2000+12)= 2000(14+12)= 2000. 168
b= 2000 . 169
vậy b>a
Ta có:
A=2012 x 2014
B = 2013 x 2013 = 2012 x 2014 + 1
Vậy B lớn hơn A
A = 2014 x (2011 + 1) = 2013 x 2012 + 2013
B = (2012 + 1) x 2013 = 2013 x 2012 + 2013
Ta thấy 2012 > 2011 nên A > B (A = B + 1)