=x³/(x-1) -(x²+x+1)
=x³/(x-1) -(x-1)(x²+x+1)/(x-1)
=x³/(x-1) -(x³-1)/(x-1)
=1/(x-1)对吗 感觉跟我题目不一样啊对的
x-1分之x的立方-x的平方-x-1
=x³/(x-1)-(x²+x+1)将后面的三项放到带有负号的括号里
=x³/(x-1)-(x-1)(x²+x+1)/(x-1)后面部分通分
=x³/(x-1)-(x³-1)/(x-1)计算后面的分子
=1/(x-1) 合并