哈又有不會的題目嘞
回答 (1)
2010-08-11 9:15 am
✔ 最佳答案
(4x-3y-14)^2 + |5x-3y-31| = 0因(4x-3y-14)^2 >= 0
|5x-3y-31| >= 0故 (4x-3y-14)^2 + |5x-3y-31| = 0 時有(4x-3y-14)^2 = 0
|5x-3y-31| = 0即
4x-3y-14 = 0.....(1)
5x-3y-31 = 0.....(2)(2)-(1) :5x - 4x - 31 + 14 = 0
x = 17代入(1) : 4*17 - 3y - 14 = 0y = 18xy = 17*18 = 306
收錄日期: 2021-04-21 22:14:40
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20100811000016KK00557