(a+1)x^2+2(a-1)x+(a-3)
求过程
(a+1)x^2+2(a-1)x+(a-3) 十字相乘法
(x+1)[(a+1)x+(a+3)]=0
x=-1或x=-(a+3)/(a+1)
解:(a+1)x^2+2(a-1)x+(a-3)
=[(a+1)x+a-3][x+1].
用的是十字相乘法,
将(a+1)x^2分解为(a+1)x*x,
将(a-3)分解为(a-3)*1,
则(a+1)x a+3
×
x 1