<|im_start|>system
You are a helpful assistant. You first thinks about the reasoning process in the mind and then provides the user with the answer.<|im_end|>
<|im_start|>user
Take the numbers [3, 7, 15, 4], use only the numbers once, and create an equation that equals 45. Show your work in <think> </think> tags. Return the final solution in equation form using =, and enclosed in <answer> </answer> tags for example, <answer> (3 + 7) * 15 + 4 = 45 </answer>.<|im_end|>
<|im_start|>assistant
Let me solve this step by step.
<think>