Answer:
perpendicular slope to line k is 4
Explanation:
calculate the slope of line k using the slope formula
m = 

with (x₁, y₁ ) = (4, 3 ) and (x₂, y₂ ) = (8, 2 )
m = 
 =
 = 
 = -
 = - 

given a line with slope m then the slope of a line perpendicular to it is
 = -
 = - 
 = -
 = - 
 = 4
 = 4
the slope of a line perpendicular to line k is 4