Yo can someone help me out ion get ittt thanks

1.) simplify 5f-f+2f

2.) simplify t^2+t^2

3.) simplify 2xmxnx8

4.) Simplify 3xtxyx8

25 points and ill give brainliest thx

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.