<|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 [5, 3, 7, 18], create an equation that equals 28. You can use basic arithmetic operations (+, -, *, /) and each number can only be used once. Show your work in <think> </think> tags. Your final answer should look like an answer block, for example <answer>9 * (4 - 5) = 1</answer>, where 9 and 4 are the numbers in parenthesis and the 5 was already used. Return the equation in <answer> </answer>.<|im_end|>
<|im_start|>assistant
Let me solve this step by step.
<think>