4. The 30-year mortgage on your house is 5 years old. It requires a monthly payment of $3000 and was issued with an interest rate of 5% (APR). Interest rates are now lower, you will pay off the old mortgage with a new mortgage, and the new mortgage has a 30-year term and interest rate of 3.75% (APR). Show your formula(s) with numbers inserted when answering the following questions. a. What was the original amount borrowed with the old mortgage? b. What is the remaining balance on the old mortgage? What will be the monthly payment on the new mortgage? d. If you continue making monthly payments of $3000, how many years and months does it take you to pay off the new mortgage? C