Question 1108549
Good work, as your answer is CORRECT!
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Here's how it works out using equations:

   x = cost of Ice Cream
   c = cost of Chocolate

   x = 2c   (given)
The problem asks to find c in terms of x. 
Divide both sides of the equality by 2 (if two things are equal then dividing each by two does not change the equality):
  x/2 = 2c/2
Simplify by cancelling the 2/2 on the right hand side:
  x/2 = c   (your answer)