Please need help I will be MARKING as BRIANILIST. thank you so much.

F(n + 1) = f(n) – 8. if f(1) = 100, what is f(6)?

Dean and karlene get paid to write songs. dean is paid a one-time fee of $20 plus $80 per day. karlene is paid a one-time fee of $25 plus $100 per day. write an expression to represent how much a producer will pay to hire both to work the same number of days on a song.

What is the area of the shaded sector?