Hey can somebody help me

How do you determine whether a relationship represented as as graph is linear or nonlinear

Me complete this proof! prove that a quadrilateral is a square. me with the steps for this proof.

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.