x-（1/1-x）-（x^3-3x+1/x^2-1）＝x-(1/1-x)-{x(x^2-1)-2x+1}/x^2-1=x+(1/x-1)-x+(2x-1)/x^2-1=(2x-1)/x^2-1+(x+1)/(x+1)(x-1)=(2x-1+x+1)/x^2-1=3x/x^2-1=(3x-1/3 )/(-1/3)^2-1=-1/(-8/9)=9/8