=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)對嗎 感覺跟我題目不一樣啊對的
x-1分之x的立方-x的平方-x-1
=x³/(x-1)-(x²+x+1)將后面的三項放到帶有負號的括號里
=x³/(x-1)-(x-1)(x²+x+1)/(x-1)后面部分通分
=x³/(x-1)-(x³-1)/(x-1)計算后面的分子
=1/(x-1) 合并