It's not a function because the x value repeated but wasn't accompanied by the same y value . there is (-2,2) and (-2,14) but if they had the same y value like (-2,2) and (-2,2) or (-2,14) and (-2,14) the table would represent a function. If you still dont understand I'll be more than happy to elaborate :)
It is definitely a. 9>5n Because it say 9 is more than five times a number and if you have any questions just comment an I'll try to help! :) Hope I helped!
