问题
选择题
(2011江苏泰州,3,3分)一元二次方程x2=2x的根是
A.x=2
B.x="0"
C.x1="0," x2=2
D.x1="0," x2=-2
答案
答案:C
x2=2x,x2-2x=0,
x(x-2)=0,
x=0,x-2=0,
x1=0,x2=2,
故选:C.
(2011江苏泰州,3,3分)一元二次方程x2=2x的根是
A.x=2
B.x="0"
C.x1="0," x2=2
D.x1="0," x2=-2
答案:C
x2=2x,x2-2x=0,
x(x-2)=0,
x=0,x-2=0,
x1=0,x2=2,
故选:C.