If $x - y = 6$ and $x + y = 12$, what is the value of $y$?
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
If $x - y = 6$ and $x + y = 12$, what is the value of $y$?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
3
If $x - y = 6$ and $x + y = 12$, what is the value of $y$?
train