怎么简单解这个?-1≤(6m-9)/(4-m)≤1

怎么简单解这个?-1≤(6m-9)/(4-m)≤1
怎么简单解这个?-1≤(6m-9)/(4-m)≤1

怎么简单解这个?-1≤(6m-9)/(4-m)≤1
即有|(6m-9)/(4-m)|<=1
|6m-9|<=|4-m|
平方得:36m^2-108m+81<=16-8m+m^2
35m^2-100m+65<=0
7m^2-20m+13<=0
(7m-13)(m-1)<=0
1<=m<=13/7

-1《-6+15/m-4《1然后再解

求m的取值范围