There has actually been a significant amount of research done on "cramming" for exams. The results point unanimously towards a conclusion that getting a full night's sleep and eating a healthy breakfast (contain lean protein and complex carbohydrates, but avoiding sugary junk food) actually improves scores compared to staying up late to study. Since the actual problems in algebra can mainly be figured out by simple logic, I'd focus on skimming the overviews of each chapter in your text book to make sure you know the appropriate terminology.
Another good strategy is looking online for sample tests from previous years. Try to answer the questions in the tests quickly in your head. If there is any particular type of question you are struggling with, that is the area you should review.