解方程:(x-1分之x)²-4(x-1分之x)+3=0
- 提问者网友:欺烟
- 2021-03-19 12:29
如何推我解到(x-1)²分之-2x+3=0
如何继续下一步?
用换元法a=x-1分之x,又该如何解
而且我的这一步(x-1)²分之-2x+3=0变成-2x+3=0 x=1.5了啊.
可是刚才的回答者说是3
- 五星知识达人网友:持酒劝斜阳
- 2021-03-19 13:56
我的过程和你不一样
你是两边乘(x-1)²吧
所以是令a=x-1分之x
则方程就说a²-4a+3=0
(a-1)(a-3)=0
a=1,a=3
所以
x-1分之x=1,x-1分之x=3
其中第一个x-1分之x=1无解
所以只有一个解
再问: 令a=x-1分之x。可是解出来的a不是X,而是x-1分之x,所以x-1分之X=3或1才对。不是x=3或一?
再答: 没错啊
再问: 原来是你算错了,你设的a是x-1分之x,所以得出来的A也是一样的。a=1或3
则x-1分之x=3 x=3x-3 x=1.5 而x-1分之x=1 0=1(不合题意,舍去)
所以做人还是相信自己为妙,你算错了
再答: 没错,不信拉倒
再问: 对,我和你的想法是一样的。只是你没把结果写出来,嗯。对!
再答: 不信拉倒!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!