(x³+y³)+(x²y+xy²)+(x+y)=0(x+y)(x²-xy+y²)+xy(x+y)+(x+y)=0(x+y)(x²-xy+y²+xy+1)=0(x+y)(x²+y²+1)=0x²+y²+1≥1>0即不会等于0所以x+y=0y=-x原式=(5x+6...