1 A bag contains 100 marbles. Some are red and the rest are black. There
are 3 red marbles for every 1 black marble. How many red marbles are in
the bag?

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.