因为a>0,b0,6-5b>0,|6-5b|=6-5b;
8b0,3a-2b>0,|3a-2b|=3a-2b;
|6-5b|+|8b-1|-|3a-2b|
=6-5b+1-8b-3a+2b
=7-11b-3a