write it out please i need to u derstand the steps

Problem 4: An enginner borrowed $15,000 from the bank payable in 10 equal end-of-year payment at i=10%. The bank agreed to reduce the interest on the loan if interest declined before the loan was fully repaid. After the 4th payment, the bank agreed to reduce the interest rate on the remaining debt to 8%. What was the amount of the equal annual end-of-year payments for each of the first 4 years. What was the amount of the equal annual end-of-year payments for each of the last 6 years