Question

若不等式组有实数解，则实数m的取值范围是（　　）              

A．m≤                       B．m＜                     C．m＞                     D．m≥

Answer 1

A【考点】解一元一次不等式组．                                                            

【专题】压轴题．                                                                              

【分析】解出不等式组的解集，根据不等式组有实数解，可以求出实数m的取值范围．              

【解答】解：解5﹣3x≥0，得x≤；                                                        

解x﹣m≥0，得x≥m，                                                                        

∵不等式组有实数解，                                                                       

∴m≤．                                                                                           

故选A．                                                                                            

【点评】本题是反向考查不等式组的解集，也就是在不等式组有实数解的情况下确定不等式中字母的取值范围，解答本题时，易忽略m=，当m=时，不等式组的解集是x=．