Well, for really long questions, you could split the question into shorter ones, which then you can post one after the other. As far as images go, you could always post a link to the image in the comments section of the question.
You can upload the picture on a free picture upload site and then post the link here. You could even do that with the question itself, if it really is that long of a question.
You could ask a question like this
How can I use this concept in this problem?
and then use a link posted in the comment section to the full-sized question.
These are just a few ideas, but I think they could work.