At the very end of the novel, Ponyboy's teachers, and especially his English teacher, are showing him a bit more compassion and understanding than they did throughout the rest of the novel.
His English teacher explains to him that he missed a great deal of work, but that if he writes a great end-of-semester essay, his grade will be raised to a C. We, the readers, find out at the very end that the actual story of The Outsiders was instigated by the writing assignment, and that Ponyboy's account was a result of completing the writing prompt.
It would be easier to get a good answer if your question were more specific, but I will try.
Close to the end of the book, Pony is having a lot of problems at school. The Socs are mad at him because he was involved in Bob's death. Pony is also starting to fail in classes because he is depressed and hopeless.
But then things turn around for him. At the end of the book, he has called his English teacher and then started to get to work on his theme. This shows that he is motivated again and will be able to succeed.