关于Pxx21的百科

• *P={x|x2=1}，Q={x|mx=1}，若QP，则m等于                       ...

• 问题详情：*P={x|x2=1}，Q={x|mx=1}，若QP，则m等于                                            （   ）      A．1                  B．-1                   C．1或-1         ...
• 2020-08-1915456