1/x+1-x+3/x^2-1除以x^2+4x+3/x^2-2x+1,其中x=-1/2

1/x+1-x+3/x^2-1除以x^2+4x+3/x^2-2x+1,其中x=-1/2

=[(x-1)-(x+3)]/(x+1)(x-1)×(x-1)^2/(x+3)(x+1)
=-4(x-1)/(x+1)^2(x+3)