So i need reasons for each of these i legit have no idea how to do proofs 3x - 4 = 2(x + 8) 3x - 4 = 2x + 16 3x = 2x + 20 x = 20 they are in order

Aprobability experiment is conducted in which the sample space of the experiment is s={7,8,9,10,11,12,13,14,15,16,17,18}, event f={7,8,9,10,11,12}, and event g={11,12,13,14}. assume that each outcome is equally likely. list the outcomes in f or g. find p(f or g) by counting the number of outcomes in f or g. determine p(f or g) using the general addition rule.