若x^2+x-3=0,则分式3-x^2-x^3/x-1=?
问题描述：
若x^2+x-3=0,则分式3-x^2-x^3/x-1=?
RT
答
x^2+x=3
(3-x^2-x^3)/(x-1)
=[3-(x^2+x^3)]/(x-1)
=[3-x(x+x^2)]/(x-1)
=[3-x*3]/(x-1)
=-3(x-1)/(x-1)
=-3