A local firm needs to pay a bank $19,000 on a date 4 months ago. This local firm is planning to pay $10,000 now and the balance in 5months.

A local firm needs to pay a bank $19,000 on a date 4 months ago. This local firm is planning to pay $10,000 now and the balance in 5months. Assuming that the bank requires 18% per year compounded monthly on overdue accounts. What should the second payment be? Please help with formulas and working, so I can understand better. thank you so much. 

CompoundingAmount that was to be paid 4 months ago $19,000 Amount a local firm plans to pay now $10,000 Balance that will be paid 5 months from now ? Rate of interest on overdue accounts 18%...