Find the first day of Mathematics (Centennial Dictionary) rational number subtraction that chapter of the title, in urgent need! Everyone help Only need the question, not the answer!
1^2-2^2+3^2-4^2+.-2002^2+2003^2
=1+(3+2)*(3-2)+(5+4)*(5-4).+(2003+2002)*(2003-2002)
=1+5+9+.4005
=1+(5+4005)*[(4005-5)/4+1]/2
=1+4010*1001/2
=2007006