(a-1)/[a^(2/3)+a^(1/3)+1]化简等于?
问题描述：
(a-1)/[a^(2/3)+a^(1/3)+1]化简等于?
答
分子立方差
原式=[a^(1/3)-1][a^(2/3)+a^(1/3)+1]/[a^(2/3)+a^(1/3)+1]
=a^(1/3)-1