During a marathon race an athlete loses 3 % of his mass. At the end of the race his mass is 67.13 kg. Calculate his mass before the race.

How do i do this activity, is appreciated

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.

How can (square root of 25) ^2 be rewritten?