To solve this problem we first call x = number of action figures, y = number of dolles. A system of two equations with two unknowns must be made to describe the problem. The system is the following:
 (x + 1) + y = 13
 1/2 * x = y.
 Then solving the system we have that x = 8 and y = 4.
 Since we know that the number of action figures is twice as many dolls plus one, then x = 8 + 1 = 9.
 Thus,
 dollos = 4
 action figures = 9