a. x^4-17x^2+72=0
b. (5^x)^2+5^x+1-1=0 呢題有個5^+1係到都唔知點解
有冇人識解方程??識就教下我thz~
2007-12-14 3:02 am
回答 (2)
2007-12-14 3:31 am
✔ 最佳答案
As follows:圖片參考：http://i238.photobucket.com/albums/ff245/chocolate328154/Maths034.jpg?t=1197545503
2007-12-13 19:34:37 補充：
唔好意思呀, 圖入面d字可能細咗d, 如果睇唔清楚嘅話就save咗佢開番再放大嚟睇啦~~~
參考: My Maths Knowledge
2007-12-14 3:29 am
a. x^4-17x^2+72=0
(x^2- 9)(x^2 -8)=0
x^2=9 or x^2=8
x= +3 , -3 , 2開方2 or-2開方2
(x^2- 9)(x^2 -8)=0
x^2=9 or x^2=8
x= +3 , -3 , 2開方2 or-2開方2
收錄日期: 2021-05-01 15:39:39
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20071213000051KK02674