挑战习题
1/5单选题
难度:

1.下列方程中有两个相等实数根的是(  )
A x2+2x+1=0
B 2x2-4x+4=0
C (x-1)2=-4
D 5x2+4x=1
提示1:
IOaKiuaWueeoi+mDveWPmOW9ouS4uuS4gOWFg+S6jOasoeaWueeoi+eahOS4gOiIrOW8jzs=
提示2:
IOWGjeWIhuWIq+iuoeeul+WIpOWIq+W8j+KWsz1iPHN1cD4yPC9zdXA+LTRhYzs=
提示3:
IOeEtuWQjuWIhuWIq+agueaNruKWs+eahOaEj+S5iei/m+ihjOWIpOaWreWNs+WPry4=
正确答案:QQ==
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