Answer:
x = Anna's age s = Sister's age
x + 5 = s
Explanation:
There is really no right answer to this question because it does not have enough information. To find the right answer for the question you would have to either have the sister's age now or you would have to know anna's age. Without this information, all you can answer this question with is an equation.
The equation would be x + 5 = s
Sorry if this is not of much help!