<|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
Using the numbers [46, 15, 30, 12], craft an equation that equates to the target of 81. You can use the basic arithmetic operations (+, -, *, /) and maintain uniqueness for each number used. Explain all your steps in detail within <think> </think> tags, and then present your final equation and answer in <answer> </answer> tags, adhering to the provided format, e.g., <answer> (2 * 4) + 15 = 23 </answer>.<|im_end|>
<|im_start|>assistant
Let me solve this step by step.
<think>