Can i raise my 2.43 GPA up with 30 extra credits?

It is surprising how a year or two of As can improve matters. I don't know the exact math. But, depending on what you need to take in order to both graduate and meet college entrance requirements, it may not be easy. Turning in all work, making sure you understand everything as you go along (ie. get a math tutor) and regular attendance (being there, not just warming the seat!) can make it easier. For most of us, we are better in one thing than in another and it just means that the rest of the stuff needs concentrated work. Don't be shy about asking for help from friends or going to afterschool tutorials to make sure you make the grades.