Answer:
Either $200 or $80 depending on the question.
Explanation:
1. Curtis paid $80
2. The vet charged $40 for the medicine. x + $40 = $120
3. If he owes the vet $120 and he paid $80 then his total bill is $200.
HOWEVER, if the question is asking what ammount he initially started with it would be $80 because that's all he has paid.