Long time ago, when I'm still new to this site. I posted 4-5 answer to different question, and all of them got downvote. I recently figured out that they're low quality answer.
So is it okay to remove them ?
You should remove them if, and only if they can not be improved. Deleting answers potentially deprives people of a solution. We (obviously) don't want to do that.
If a post can, at all, be salvaged and brought up to quality standards, this should be done instead. However, if there's absolutely no way to recover the answer, then a delete is most likely the best way to go.
This is even supported by official Stack Exchange policy. Post bans take into effect deleted posts (at a higher weight than non-deleted posts) into deciding whether you should or should not be allowed to post.