a小于0,b大于0,|5-2a|-|5a-b|+|3a-1|-|4b-a|

问题描述:

a小于0,b大于0,|5-2a|-|5a-b|+|3a-1|-|4b-a|

=(5 2a)-(5a b) (3a 1)-(4b a)=5 2a-5a-b 3a 1-4b-a=6-a-5b