Factor $36-4x^2$ completely.
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Factor $36-4x^2$ completely.
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
4(3-x)(3+x)
Factor $36-4x^2$ completely.
train