*Hint: When the slope of a line is perpendicular, it would have the negative reciprocal.
First, let's simplify this equation into y = mx + b format.
y - 3 = 5(x - 4)
y - 3 = 5x - 20
y = 5x - 17
Since 5 is the slope of this equation, the negative reciprocal would be -1/5.
Answer: -1/5