Simplify $(5-3i)(-4+3i)$.
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Simplify $(5-3i)(-4+3i)$.
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
-11 + 27i
Simplify $(5-3i)(-4+3i)$.
train