If we get a Negative Trust, how to eliminate it? Is it possible to remove Negative Trust by getting a Positive Trust?
There are two ways for negative trust to be removed. First is that the default trust user or a trusted user who gave one negative feedback(negative trust) must remove their negative feedback. Another way is to gain positive trust to counter the red trust, but the negative feedback will still be there unless removed.
Should you ask the person giving the Negative Trust to remove it?
You may do so if you think the feedback is unreasonable. It will be up to him/her though to remove it or not.
Where can I get information about Trust?
You can get more information about it in meta.