What value of $x$ will give the minimum value for $9x^2 + 18x + 7$?
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
What value of $x$ will give the minimum value for $9x^2 + 18x + 7$?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
-1
What value of $x$ will give the minimum value for $9x^2 + 18x + 7$?
train