丨2x-1丨-3丨m丨=-1
x=3
|6-1|-3|m|=-1
5-3|m|=-1
-3|m|=-6
|m|=2
m=+-2
当m=2时
3m的平方-m-1
=12-2-1
=9
当m=-2时
3m的平方-m-1
=12+2-1
=13
=