<|im_start|>system
You are a helpful assistant. You first think about the reasoning process in the mind and then provide the user with the answer. You should try to truely solve the question by yourself without cheating.  <|im_end|>
<|im_start|>user
 Let x be the number of old songs Zoe deleted from her mp3 player and y be the number of new songs she added. If Zoe initially had 15 songs on her mp3 player and ended up with twice as many songs as she had before, find the values of x and y. Show your work in <think> </think> tags. And return the final answer in <answer> </answer> tags.<|im_end|>
<|im_start|>assistant
Let me solve this step by step.
<think>
user
15
Let x be the number of old songs Zoe deleted from her mp3 player and y be the number of new songs she added. If Zoe initially had 15 songs on her mp3 player and ended up with twice as many songs as she had before, find the values of x and y.
test