21y+14
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Expand the following expression: $7(3y+2)$
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
21y+14
Expand the following expression: $7(3y+2)$
train