please I need to know how it is done on BAII plus

17. A borrower took out a 30-year fixed-rate mortgage of $2,250,000 at a 7.2 percent annual rate. After five years, he wishes to pay off the remaining balance. Interest rates have by then fallen to 7 percent. How much must he pay to retire the mortgage (to the nearest dollar)?

    A. $2,122,426 B. $2,225,330 C. $2,015,678 D. $2,212,041 E. $1,999,998 please I need to know how it is done on BAII plus

18. A homeowner could take out a 15-year mortgage at a 5.5 percent annual rate on a $195,000 mortgage amount, or she could finance the purchase with a 30-year mortgage at a 6.1 percent annual rate. How much total interest over the entire mortgage period could she save by financing her home with the 15-year mortgage (to the nearest dollar)?

    A. $230,408 B. $190,105 C. $155,612 D. $144,325 E. $138,612