ax²-(3a+1)x+2(a+1)=0
a -(a+1)
1 -2
(ax-(a+1))(x-2)=0
x=2 x=(a+1)/a =1+1/a
a≠0
兩個(gè)不相等的實(shí)數(shù)根
(a+1)/a ≠2
a+1≠2a
a≠1
x1=2 x2=(a+1)/a
x1- x1²+ x2=1-a
2-4+1+1/a=1-a
-2+1/a+a=0
a²-2a+1=0
(a-1)²=0
a=1
無(wú)解
x1=(a+1)/a x2=2
(a+1)/a-((a+1)/a)²+2=1-a
(a+1)/a-((a+1)/a)²+(1+a)=0
(a+1)(1/a-(a+1)/a²+1)=0
a+1=0 1/a-(a+1)/a²+1=0
a=-1
解1/a-(a+1)/a²+1=0
a-a-1+a²=0
a²=1
a=±1
a的值是 a=-1