So to find the answer to this, you have to consider that

- half because half the pocket money (x) was spend on clothes, then plus 9 because that's how much extra she gained and 13 because that was the result of all the changes.
To solve this, first subtract 9 from both side, which leaves you with

and

is the same as

, so to solve this, multiply both sides of the equation by two, resulting in

. SO from this we can conclude that the weekly allowance is $8
8 to 16
2 to 4
13 to 26
5 to 10
6 to 12
The answers to your question would be A. Housing B. medical expenses C. Groceries