Can you solve question (10) I solved question 9 but I need help in d and e please solve it as engineering economics equations thanks

9) Luis purchased a condominium five years ago. At that time he took a 15-year $100,000 home mortgage at 10% per year, compounded monthly. Payments on the loan are made at the end of each month a) What is Luis monthly payment? b) What is the remaining principal on Luis' mortgage after making 5 years worth of mortgage payments? c) What is the total interest that Luis has paid to date? 10) (Follow-on to Problem #9) Today interest rates have fallen to 7%. Luis wants to explore refinancing his home to lower his obligation. The mortgage company will charge Luis a flat fee of $3000 for refinancing his mortgage. d) If Luis refinanced his mortgage today, what would be his new monthly payment? e) Luis is considering relocating to a new city in the near future. How many more months would Luis have to live in his home to make the decision to refinance worthwhile? Assume the MARR is 8% per annum