若ab大于0,则有___ ,若ab=0,则有_____,如果a+b大于0,ab小于0,则有_____.
问题描述:
若ab大于0,则有___ ,若ab=0,则有_____,如果a+b大于0,ab小于0,则有_____.
答
若ab大于0,则有_a,b同号__ ,若ab=0,则有_a=0或b=0或a,b都=0____,如果a+b大于0,ab小于0,则有_a>-b>0>b____.速度!