x等于他的倒数x^2=1x=±1而分式x2+2x-3/x-1有意义,因此,x≠1所以,x=-1x2+2x-3/x-1除以x+1+3/x2-3x+1=(x+3)(x-1)/(x-1)÷(x+1)+3/(x^2-3x+1)=(x+3)/(x+1)+3/(x^2-3x+1)要分式有意义,必须,x≠-1所以,x=1所以,原分式=(1...