Answer:
-4
Step-by-step explanation:
The equation of line one is;
y = 1/4x + 5
The slope of this line is [tex]\frac{1}{4}[/tex]
Let the slope of line two be 'a'.
a × [tex]\frac{1}{4}[/tex] = -1 (the product of slopes of two perpendicular lines is equal to -1)
a = -1 ÷ [tex]\frac{1}{4}[/tex] = -4