(x1+x2)的三次方
问题描述:
(x1+x2)的三次方
答
(x1+x2)³
=x1³+3x1²x2+3x1x2²+x2³
(x1+x2)的三次方
(x1+x2)³
=x1³+3x1²x2+3x1x2²+x2³