x3-y3-3xy=1 x-y=?
问题描述：
x3-y3-3xy=1 x-y=?
答
(x-y)^3=x³-3x²y+3xy²-y³ 则
x3-y3-3xy=1
(x-y)^3+3x²y-3xy²=1
(x-y)^3+3xy(x-y)=1
(x-y)((x-y)2+3xy)=1