What more can I do?

I feel like all my games are filled with trolls. I had someone who afk'd first ten mintes, came back and fed. Then he rage quit. Like...? Its not just once a week, its two or three times a day. So I try to win the 4v5, but I'm simply not that good. And I know "its possible, it can be done" but Im not THAT good. I believe I am better then my opposition, but not by enough to carry my team. Its so frustrating. So what I'm asking is, How do I win a 4v5 when my team sucks balls. Just pretend I'm the only competent one, how do I single handed win?