设A﹙n-1﹚是A的n-1阶顺序主子式,P﹙n-1﹚＝|A﹙n-1﹚| ﹙行列式﹚|A|＝|A﹙n-1﹚ X || X′ ann | ﹙X＝﹙an1 an2 ……an n-1﹚′ ＝﹙按第二块行折开﹚|A﹙n-1﹚ X |+|A﹙n-1﹚ X || 0 ann | | X′ 0 |＝annP﹙n-1...