a= 18x19+20x21-22x23+2x[15+3x(40^2-39^2)]=
= 342+420-506+2x[15+3x(1600-1521)]=
= 256+2x(15+3x79)=
= 256+2x(15+237)=
= 256+2x252=
= 256+504=760
b= 2013x2012+2013x2011-2013x2022+7x[9+2x(53^2-52^2)]
=
= 2013(2012+2011-2022)+7x[9+2x(2809-2704)]
=
= 2013x2001+7x(9+2x105)
=
= 2013x2001+7x(9+210)
=
= 4028013+7x219
=
= 4028013+1533
=
=4029546
b>a