（1+0.97+0.215）*（0.97+0.215+0.567）-（1+0.97+0.215+0.567）*（0.97+0.215）=（0.97+0.215）*（0.97+0.215+0.567）+1*(0.97+0.215+0.567）-（0.97+0.215+0.567）*（0.97+0.215）-1*（0.97+0.215）=(1-0.97-0.215)*(0.97+0.215+0.567)+(0.97+0.215-1)*(0.97+0.218+0.567)=0
2004*2004+2003*2003-2004*2003-2003*2002
=2004*2004-2004*2003+2003*2003-2003*2002
=2004*(2004-2003)+2003*(2003-2002)
=2004*1+2003*1
=2004+2003
=4007