Please help Please help

What is the common difference in the following arithmetic sequence 7,3,-1,-5

F(x)=5/6x+3 which of the following is true

Which of these would have been most likely to have been a carpetbagger during the reconstruction era? a) a new york businessman who relocated to mississippi b) a former slave who was able to buy land in birmingham c) a carolina-born politician who supported the democratic d) a former confederate officer who owned a farm in memphis eliminate