二次方程......
回答 (2)
2007-09-15 11:26 pm
✔ 最佳答案
9x^4-40x^2+16=0let a=x^2, we have
9a^2-40a+16=0
(9a-4) (a-4)=0
a=4/9 or a=4
since a=x^2
therefore x=2/3 or x=2
2007-09-15 11:32 pm
y=x^2,
9y-40+16=0
(9y-4)(y-4)=0
y=4/9 or 4
As y=x^2,
x= 2/3 or -2/3 or 2 or -2
9y-40+16=0
(9y-4)(y-4)=0
y=4/9 or 4
As y=x^2,
x= 2/3 or -2/3 or 2 or -2
參考: ME
收錄日期: 2021-04-13 13:29:52
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