Eddie the elf made 13 toys one day in the workshop. some were dolls and the rest were action figures. the number of action figures he made was one more than twice the number of dolles he made. how many dolls and action figures did eddie make?

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

C. a,b, and d are not numbers. they are expressions.