Can you delete an answer?
No, contributors cannot delete answers.
Contributors don't have the ability to delete an answer.
As you would imagine, this ability would be something very difficult to supervise in order to make sure that it's not being abused.
If, for some (good) reason, you want an answer deleted, you can let us know about it in that respective question's comments section.
The same is true for questions. You cannot delete a question you've posted, but you can use the Close question option and suggest a reason for why you want it closed.
More on that here: