Ineed so much i beg you it's easy but ain't got no time

Find an equation for the linear function which has slope -10 and x-intercept -7

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.

Given δjkl : δxyz, find x. a)10 b)12 c)16 d)20