挑战习题
1/5单选题
难度:

1.下列方程是一元二次方程的是()
A x2-1=y
B(x+2)(x+1)=x2
C 6x2=5
D x2
提示1:
IOiAg+Wvn+S4gOWFg+S6jOasoeaWueeoi+eahOWumuS5ie+8jOS4gOWFg+S6jOasoeaWueeoi+aMh+eahOaYr++8muWPquWQq+acieS4gOS4quacquefpeaVsO+8jOacquefpeaVsOeahOacgOmrmOasoeaVsOaYrzLnmoTmlbTlvI/mlrnnqIs=
提示2:
IOagueaNrui/meS4quWumuS5ie+8jOWvueS4iui/sOWbm+S4qumAiemhueWPmOW9ouS5i+WQjui/m+ihjOiuqOiuuuWNs+WPrw==
正确答案:Qw==
PGRpdj7op6PvvJpB44CB5piv5LqM5YWD5LqM5qyh5pa556iL77yM5pWF5pys6YCJ6aG56ZSZ6K+v77ybPGJyPkLjgIHljp/mlrnnqIvlj6/ljJbkuLrvvJozeCsyPTDmmK/kuIDlhYPkuIDmrKHmlrnnqIvvvIzmlYXmnKzpgInpobnplJnor6/vvJs8YnI+Q+OAgeespuWQiOS4gOWFg+S6jOasoeaWueeoi+eahOWumuS5ie+8jOaVheacrOmAiemhueato+ehru+8mzxicj5E44CB5piv5YiG5byP5pa556iL77yM5pWF5pys6YCJ6aG56ZSZ6K+vLiA8YnI+5pWF6YCJQy4gPC9kaXY+