是9-x²分之6原式=(x²+3x+9)/(x-3)(x²+3x+9)-6/(x-3)(x+3)-(x-1)/2(x+3)=1/(x-3)-6/(x-3)(x+3)-(x-1)/2(x+3)=[2(x+3)-12-(x-1)(x-3)/[2(x+3)(x-3)]=(2x+6-12-x²+4x-3)/[2(x+3)(x-3)]=-(x²-6...