约分：x^4+x³y-xy²-y^4／x^4＋x³y－xy³＋y^4急用!

Question

约分：x^4+x³y-xy²-y^4／x^4＋x³y－xy³＋y^4
急用!

Answer 1

分子第三项应该是xy³
分母第二项应该是-x³y
分子=x³(x+y)-y³(x+y)
=(x³-y³)(x+y)
=(x-y)(x+y)(x²+xy+y²)
分母=x³(x-y)-y³(x-y)
=(x³+y³)(x-y)
=(x+y)(x-y)(x²-xy+y²)
所以约分=(x²+xy+y²)/(x²-xy+y²)