zJanly

摘要： 1/[(a-x)(b-x)(c-x)]≡ A/(a-x) +B/(b-x)+C/(c-x)=>1≡ A(b-x)(c-x) +B(a-x)(c-x)+C(a-x)(b-x)x=a =>A= 1/(b-a)(c-a)x=b =>B= 1/(a-b)(c-b)x=c =>C= 1/(a-c)(b-c)i 阅读全文