解:x+y=m x-y=n ∴ x=﹙m+n﹚/2 y=﹙m-n﹚/2 x·y=﹙m²-n²﹚/4 ∴ ﹙x³+y³﹚²+﹙x³-y³﹚² =﹙x+y﹚²﹙x²-xy+y²﹚²+﹙x-y﹚²﹚﹙x²+xy+y²﹚² =m²[﹙x-y﹚²+xy]²+n²[﹙x+y﹚²-xy]² =m²﹙n²+xy﹚²+n²﹙m²-xy﹚² =m²·[﹙m²+3n²﹚/4]²+n²·[﹙3m²+n²﹚/4]²