x≤m+1x>3m-1若无解则3m-1≥m+1 2m≥2 m≥1
不等式组 x<=m+1 x>3m-1 无解必须 m+1<=3m-1-2m<=-2m>=1即m>=1时 不等式组无解
解:由题意:3m-1＞=m+1解得m＞＝1
