Does anyone know alot about math??? Math Taks this Wed and i am nervous and i need it to Graduate! Please help?

Im a 12 grader whos lost alot of education due to a sickness that made me behind almost 3 years and recently i havent been able to have math cles! ive already taken the math test twice! If u have any good options like tips, hints, tricks, or good sites to study i would appreciate it! i need this bad.. thank u.