I need step!!
1. If a = b+3cd/b-3cd, then c=?
2. If s = n/2[2a+(n-1)d], then d=?
收錄日期: 2021-04-12 21:22:34
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20061122000051KK02506