(x+y)(x²-xy+y²)=x³+y³怎么推导的,具体点,一步一步来x³+y³=(x+y)(x²-xy+y²)是怎么推导的

问题描述:

(x+y)(x²-xy+y²)=x³+y³怎么推导的,具体点,一步一步来
x³+y³=(x+y)(x²-xy+y²)是怎么推导的

=x(x²-xy+y²) +y(x²-xy+y²)
=x³-x²y+xy²+x²y-xy²+y³
=x³+y³
x³+y³
=x³-x²y+xy²+x²y-xy²+y³
=x(x²-xy+y²) +y(x²-xy+y²)
=(x+y)(x²-xy+y²)