(10.5.6)--1.2.4行列式按行（列）展开

31,2213332112322311322113312312332211aaaaaaaaaaaaaaaaaa333231232221131211aaaaaaaaa例如3223332211aaaaa3321312312aaaaa3122322113aaaaa333123211333312321123332232211aaaaaaaaaaaaaaa一、余子式与代数余子式在阶行列式中，把元素所在的第行和第列划去后，留下来的阶行列式叫做元素的余子式，记作naijijn1ija.Mij记i+jijijA=-1M，叫做元素的代数余子式．ija例如444342413...