急救!!! 若(C-B):(B-A)=2:1,(B+A):(B:C)=5:6 求A:B:C。  *如果答得完整,有解釋,清楚,將會選為最佳回答。(10分)?

2020-01-05 11:17 am

回答 (1)

2020-01-05 6:39 pm
(C-B):(B-A) = 2:1 就是 (C-B)/(B-A) = 2/1 = 2, 
則 C-B = 2(B-A),  整理得 2A-3B+C = 0

"(B+A):(B:C)" 疑是 "(B+A):(B+C)" 之誤植?
(B+A):(B+C) = 5:6 相當於 (B+A)/(B+C) = 5/6,
則  6(B+A) = 5(B+C), 整理得 6A+B-5C = 0

聯立兩方程式, 以 C 表示 A, B 之解得:
  A = (7/10)C, B = (8/10)C
即  A:C = 7:10, B:C = 8:10
故 A:B:C = 7:8:10


收錄日期: 2021-04-26 12:16:02
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20200105031747AAUJk5a

檢視 Wayback Machine 備份