3b^3-3b^3+12b-8b^3-3b+5=9b-8b^3+5
xy-6x+8x-xy-11=-6x+8x
2a^2+5a-4-2a^3-5a^2+3=-2a3+3a2+5a-1
6a^2b-5ab^2+2ab^2-3a^2b=3a2b-3ab2
3b^3-3b^3+12b-8b^3-3b+5=9b-8b^3+5
xy-6x+8x-xy-11=-6x+8x
2a^2+5a-4-2a^3-5a^2+3=-2a3+3a2+5a-1
6a^2b-5ab^2+2ab^2-3a^2b=3a2b-3ab2