|a1 x x ... x|

x a2 x ... x

x x a3 ... x

.................

x x x ... an

r2-r1、r3-r1、...、rn-r1

=|a1 x x .... x|

x-a1 a2-x 0 .... 0

x-a1 0 a3-x .... 0

............................

x-a1 0 0 .... an-x

r1-r2x/(a2-x)-r3x/(a3-x)-...-rnx(an-x)

=|m 0 0 ....... 0| 【m=a1+(a1-x)/(a2-x)+...+(a1-x)/(an-x)

x-a1 a2-x 0 ....... 0

x-a1 0 a3-x ....... 0

..............................

x-a1 0 0 ....... an-x 【是個《下三角》

=m*∏(ak-x) [k=2 to n]

=[a1+(a1-x)∑1/(ak-x)]*∏(ak-x) 【 k= 2 to n】