解:(k-1)/(x²-1)-1/(x²-x)=(k-5)/(x²+x)(k-1)/[(x+1)(x-1)]-1/[x(x-1)]=(k-5)/[x(x+1)] 方程两边同时乘x(x+1)(x-1)(k-1)x-(x+1)=(k-5)(x-1)kx-x-x-1=kx-k-5x+5kx-x-x-kx+5x=-k+5+13x=6-kx=(6-k)/3∵ x=-1是增根∴ (6-k)/3=-16-k=-3k=9