Question

x²+xy+y²／x³-y³

Answer 1

当x²+xy+y²不等于0且x不等于y时：
x²+xy+y²／x³-y³
=x²+xy+y²／[(x-y)(x²+xy+y²)]
=1/
(x-y)
当x²+xy+y²等于0或者x等于y时，该题无解。