6（a+b)=10(b+c)=5(c+a),且ab+be+ca=189,求ab-bc-ca=?
回答 (1)
2017-05-07 2:32 pm
✔ 最佳答案
Sole改為c
[6，10，5]=60
6(a+b)=10(b+c)=5(c+a)=60p
a+b=10p
b+c=6p
c+a=12p
a+b+c=14p
a=8p，b=2p，c=4p
ab+bc+ca
=16p^2+8p^2+32p^2
=56p^2
56p^2=189
p^2=27/8
ab－bc－ca
=16p^2-8p^2－32p^2
=－24p^2
=－81
收錄日期: 2021-04-30 22:07:29
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20170507031346AA3EMY5