如果,试问并说明理由.

若<img src="https://s3.cn-north-1.amazonaws.com.cn/qingshuxuetang/examination/imgUplod/155419380069973105f66ea6f4fad8c7ee05585538d02image24.png"style="width:59px;height:21px;"/>,则<img src="https://s3.cn-north-1.amazonaws.com.cn/qingshuxuetang/examination/imgUplod/1554193800737a5e1ddd0109046cca56c52200f5b4ab3image26.png"style="width:89px;height:21px;"/>. ......................(2分)<br/>否则,若<img src="https://s3.cn-north-1.amazonaws.com.cn/qingshuxuetang/examination/imgUplod/1554193800799185db3ffdbde48b8807aa434fcefbe74image27.png"style="width:115px;height:21px;"/>,则<img src="https://s3.cn-north-1.amazonaws.com.cn/qingshuxuetang/examination/imgUplod/1554193800842a40c6855a42d4e2bac82a8711e76f92fimage28.png"style="width:65px;height:21px;"/>,<img src="https://s3.cn-north-1.amazonaws.com.cn/qingshuxuetang/examination/imgUplod/15541938008764d259d73830745a499c3a6a6bdd5a9e9image29.png"style="width:51px;height:21px;"/>.又因<img src="https://s3.cn-north-1.amazonaws.com.cn/qingshuxuetang/examination/imgUplod/1554193800904c343d55478e84adb9bd9d8783374fe99image24.png"style="width:59px;height:21px;"/>,所以<img src="https://s3.cn-north-1.amazonaws.com.cn/qingshuxuetang/examination/imgUplod/15541938009395fe02018e2e144a7a5554229a10afc26image30.png"style="width:32px;height:21px;"/>,<img src="https://s3.cn-north-1.amazonaws.com.cn/qingshuxuetang/examination/imgUplod/155419380100469edf2676f01453591c7d7a8fb7a5105image31.png"style="width:31px;height:21px;"/>有且只有一个成立.不妨设<img src="https://s3.cn-north-1.amazonaws.com.cn/qingshuxuetang/examination/imgUplod/15541938010485d661cb57fba403ca349bc3aea2faae1image30.png"style="width:32px;height:21px;"/>,又<img src="https://s3.cn-north-1.amazonaws.com.cn/qingshuxuetang/examination/imgUplod/155419380111570dd35deff8f454ba287ee110b85762fimage28.png"style="width:65px;height:21px;"/>,所以<img src="https://s3.cn-north-1.amazonaws.com.cn/qingshuxuetang/examination/imgUplod/15541938011590162c3b34d6e49cba2b08ba91ca22865image31.png"style="width:31px;height:21px;"/>.矛盾!(8分)