After drawing a line segment, what is the second step in constructing its perpendicular bisector?

I’m stuck on this i don’t understand.

What’s the answer ? use the picture to see the problem

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.