9x^4+12x^3-2x^2-7x+2000
=9x^4-3x^3+15x^3-5x^2+3x^2-x-6x+2000
=(3x²-x)(3x²+5x+1)-6x+2000
=3x²+5x+1-6x+2000
=3x²-x+1+2000
=1+1+2000
=2002