题目内容
(2011安徽,8,4分)一元二次方程x(x-2)=2-x的根是( )
A.-1 | B.2 | C.1和2 | D.-1和2 |
D
x(x-2)=2-x,
x2-2x=2-x,
x2-2x+x-2=0,
x2-x-2=0,
(x-2)(x+1)=0,
x-2=0或x+1=0,
解得x1=2,x2=-1;
故答案为x1=-1,x2=2.选D
x2-2x=2-x,
x2-2x+x-2=0,
x2-x-2=0,
(x-2)(x+1)=0,
x-2=0或x+1=0,
解得x1=2,x2=-1;
故答案为x1=-1,x2=2.选D
练习册系列答案
相关题目