<|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 [12, -7, -99, 50], create an equation that equals 85. You can use basic arithmetic operations (+, -, *, /) and each number can only be used once. Show your work in <think> </think> tags. Draw attention to your steps and rationale but do not solve the equation in the prompt. Just provide the numbers and the target. And return the final equation and answer in <answer> </answer> tags, for example <answer> (1 + 2) * (3) = 6 </answer>.<|im_end|>
<|im_start|>assistant
Let me solve this step by step.
<think>