用取平方根法解下列各方程
(如有需要,取答案准至二位小數)
5. (2y - 3)2 = 8
7. (y + 2.5)2 = 3.25
急,大家可唔可以教吓我解方程啊3
2008-09-07 4:51 pm
回答 (2)
2008-09-07 6:48 pm
✔ 最佳答案
5)(2y - 3)2 = 8
2y - 3 = √8
2y = (2√2) + 3
y = [(2√2) + 3] / 2
y = [(2√2) + 3] / 2 or [ - (2√2) + 3] / 2
∴ y = 2.91 or 0.09
7)
(y + 2.5) 2 = 3.25
(y + 5/2) 2 = 13/3
y + 2.5 = √3.25
y = (√3.25) – 2.5
y = (√3.25) – 2.5 or - (√3.25) – 2.5
∴ y = - 0.70 or - 4.30
希望幫到您！
2008-09-07 5:09 pm
收錄日期: 2021-04-23 20:40:17
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20080907000051KK00434