maths
回答 (2)
2009-12-04 1:20 am
✔ 最佳答案
the answer is 1/a-1/c 
2009-12-03 11:34 pm
1/(ab)+1/(bc)
=c/(abc)+a/(abc)
=(c+a)/(a+b+c)
=c/(abc)+a/(abc)
=(c+a)/(a+b+c)
收錄日期: 2021-04-13 16:57:47
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20091203000051KK00472