Respuesta :
					                   Let x be the cost of the gum 15 years ago.
This gives the equation:-
4x - 4 = 50
4x = 54
x = 13.5 cents
Answer 13.5 cents
					                
					             This gives the equation:-
4x - 4 = 50
4x = 54
x = 13.5 cents
Answer 13.5 cents