（x+y）（x²-xy+y²）=x³+y³怎么推导 - 知识问答

（x+y）（x²-xy+y²）=x³+y³怎么推导的,具体点,一步一步来

1个回答

=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)

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