(x+3)^2-4(x+3)(x-3)+3(x-2)^2
=x^2+6x+9-4(x^2-9)+3(x^2-4x+4)
=x^2+6x+9-4x^2+36+3x^2-12x+12
=-6x+57 其中x=-2013
=12135