Step-by-step explanation:
AB = 72 so, then FB would be half of that
so 72 divided by 2 would be 36
5x+1=36 then do substitution
-1 from both sides (from +1 you gotta do the inverse)
5x = 35
divide 5 from both sides because in between 5 and x is a times so the inverse of that is divide
x = 7
