Please answer properly!!!

Acomputer store buys a computer system at a cost of $370.80. the selling price was first at $ 618, but then the store advertised a 20 % markdown on the system. answer parts a and b. a. find the current sale price.

How do i find the missing angle measure in a polygon

Raymond took out a 25-year loan for $135,000 at an apr of 3.6% compounded monthly. if his bank charges a prepayment fee of 6 months' interest on 80 % of the balance, what prepayment fee would he be charged for paying off the loan 5 years early?