What is the slope of the line that passes through the points (−3,−3) and (−9,5)?

How do you use the elimination method for this question? explain, because i really want to understand!

Randy and trey take turns cleaning offices on the weekends. it takes randy at most 4 hours to clean the offices. it takes trey at most 6 hours to clean the offices. what is the greatest amount of time it would take them to clean the offices together? 2.4 hours 2.5 hours

Jahdzia wears her winter coat when the temperature is colder than -4 degrees celsius. write an inequality that is true only for temperatures (t) at which jahdzia wears her winter coat.