Rola Inc. borrowed $42 000.00 at 7% compounded semi-annually. The loan is repaid by payments of $4700.00 due at the end of every 6 months.

a) How many payments are needed? Answer: 11

b)How much of the principal will be repaid by the 6th payment? Answer: $3836.23 What are the formulas to get the answers - and how did you find them ? I just need to understand the proper way to show work for these! Thank You