When 2 roomates have different (1 710 & 1 544) credit scores asap!!!!!!!!!!?

It shouldn't be a problem. If you rent from a regular landlord (person) rather than a property management company, you'll probably have less chance of them checking your credit. Even if they do check your credit, a simple explanation about the hospital bills along with showing your recent paystubs and ability to pay should calm any fears. Plus you have a good credit roommate and that will help too. You have what we call "compensating factors" in the mortgage industry.