really wonderful. there are no (n-1)th equition .

來源: 2010-09-14 10:43:52 [博客] [舊帖] [給我悄悄話] 本文已被閱讀:

by using -a1(b2+c3b3+...+cnbn)/b1-(b2+c3b3...+cnbn)x as the first factor,the all terms with x are crossed out in the sum of all factors.
then the n-1 equitions are next n-1 factors = 1/n of the sum of all factors which do not contain any terms with x.