挑战习题
1/5单选题
难度:

1.已知一元二次方程:①x2+2x+3=0,②x2-2x-3=0. 下列说法正确的是()
A ①②都有实数解
B ①无实数解,②有实数解
C ①有实数解,②无实数解
D ①②都无实数解
提示1:
IOeUseS6jui/meS4pOS4quaWueeoi+mDveaYr+S4gOWFg+S6jOasoeaWueeoi++8jOWPr+mAmui/h+axguWHuuKRoOOAgeKRoeeahOWIpOWIq+W8j+eahOaWueW8j+WIpOaWreino+eahOaDheWGteOAgg==
提示2:
IOWFt+S9k+S+neaNru+8muKRoOW9k+KWs++8njDml7bvvIzmlrnnqIvmnInkuKTkuKrkuI3nm7jnrYnnmoTkuKTkuKrlrp7mlbDmoLnvvJvikaHlvZPilrM9MOaXtu+8jOaWueeoi+acieS4pOS4quebuOetieeahOS4pOS4quWunuaVsOague+8m+KRouW9k+KWs++8nDDml7bvvIzmlrnnqIvml6Dlrp7mlbDmoLkuIOWNs+WPr+W+l+WHuuetlOahiC4=
正确答案:Qg==
PGRpdj7op6PvvJrmlrnnqIvikaDnmoTliKTliKvlvI/ilrM9NC0xMj0tOO+8jOWImeKRoOayoeacieWunuaVsOino++8mzxicj7mlrnnqIvikaHnmoTliKTliKvlvI/ilrM9NCsxMj0yMO+8jOWImeKRoeacieS4pOS4quWunuaVsOinoy4gPGJyPuaVhemAiUIuIDwvZGl2Pg==