I can't tell whether you could increase your credit from 638 to 750 for a couple of reasons.
First, paying off a student loan will not always help you with credit score because it's a positive thing to have a loan or mortgage in your credit record. It shows that you have stable credit.
Second, paying off your credit card will help your credit score but depending on how much you owed and what your credit limit are. For example, if your credit limit is $25,000 and you owed $2,500 then paying it off will increase your score but not going to be hundread points. On the other hand, if your credit limit is $4,000 and you owed $2,500 then I'm sure you can easily increase 50 to 100 points on your credit score. It affect two factors of your account calls "The ability to pay off your debts" and "Debt Ratio".