x^4+2x^3-2x+2007
=x^2(x^2+x)+x^3-2x+2007
=x^3+x^2-2x+2007
=x(x^2+x)-2x+2007
=2007-x
x^2+x=1
解得x=（-1±√5）/2
故原式=2007-(-1±√5）/2