To solve this I would say -
For those that have made the answerer's acknolwege that they are familar with the problem and have proved so by showing there work either ina picture or in text. The answer then can show them the whole problem in one full answer on what they did and where they screwed up.
For those who do not post how they have solved the problem and why they need help, the answere's can assume they are clueless on how to solve the problem therefore indicating that they may not understand the problem may jsut be throwing homework on here to maintain a grade, the answers can ask question's to indicate if this is true or not, if it is true then the answerer should give helpful tip's on how to solve the problem rather than give the full answer.