(x+1)(x-2)=x+1
解:(x+1)(x-2)-(x+1)=0
(x+1)(x-2-1)=0
(x+1)(x-3)=0
x1=-1,x2=3
答案:x1=3,x2=-1
解析:
先将多项式乘以多项式展开,再利用十字相乘法求出x的值,具体过程如下:
x^2-x-2=x+1
x^2-2x-3=0
(x-3)(x+1)=0
x=3或x=-1
(x+1)(x-2)=x+1
变为(x+1)(x-3)=0,
解得x1=-1,x2=3.
X=-1或X=3
(x+1)(x-2)=x+1
(x-1)(x-2-1)=0
(x-1)(x-3)=0
x=1 or 3