因为a、b互为相反数,
所以,A+B=0;
又c、d互为倒数,
C*D=1
x^2-(a+b+cd)x+(a+b)^2003+(-cd)^2003
=X^2-(0+1)X+(0)^2003+(-1)^2003
=4-X+0-1
=1或5