Rearranging and grouping, we obtain $(19x - 4x) + (1 - 81) = \boxed{15x - 80}$.
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Simplify the following expression in $x$: $$19x + 1 - 4x - 81.$$
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
15x - 80
Simplify the following expression in $x$: $$19x + 1 - 4x - 81.$$
test