Does Yahoo deduct points in Answers when you ask a question?

It's because Yahoo Answers encourages people to earn points by answering questions. You can however, earn back those points by voting for Undecided Questions.

Since you're in Level 3 you can vote 60 questions which will give you 1 point per question.

Yes, they do -5 points, I think this is to deter people asking useless questions and only if you really need help to ask, you get points other ways even by voting, like if you look at all the questions you are answering and the questioner doesn't vote anyone Best Answer you can go in and vote on your answer! I am the voter and I get points by voting that is my key in going up 1 point by 1 point.

asking a question cost you 5 points.