What is the slope of a line perpendicular to the line whose equation is $\frac{x}4-\frac{y}5=1$? Express your answer as a common fraction.
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
What is the slope of a line perpendicular to the line whose equation is $\frac{x}4-\frac{y}5=1$? Express your answer as a common fraction.
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
-\frac{4}{5}
What is the slope of a line perpendicular to the line whose equation is $\frac{x}4-\frac{y}5=1$? Express your answer as a common fraction.
train