化简:{(x3-1)/(x2+x+1)}+{(x3+1)/(x+1)}-{(x3-x)/(x-1)}
问题描述:
化简:{(x3-1)/(x2+x+1)}+{(x3+1)/(x+1)}-{(x3-x)/(x-1)}
答
原式=(x-1)(x²+x+1)/(x²+x+1)+(x+1)(x²-x+1)/(x+1)-x(x+1)(x-1)/(x-1)
=(x-1)+(x²-x+1)-(x²+x)
=x-1+x²-x+1-x²-x
=-x