Simplify $(x+3)(x-1) - x(x+2)$.
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Simplify $(x+3)(x-1) - x(x+2)$.
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
-3
Simplify $(x+3)(x-1) - x(x+2)$.
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