Question 714627
(k,5) and (4,-1) is perpendicular to the line containing points (2,-2) and (1,-5).

(k,5) and (4,-1)  
slope = (y2-y1)/(x2-x1)
plug the values

(-1-5)/(4-k)= -6/(4-k)

(2,-2) and (1,-5).

slope = (-5-(-2)/(1-2)=-3/-1  = 3


The slopes of perpendicular lines are negative reciprocal of each other

m1*m2 = -1


((-6)/(4-k)) *3 =-1

-18= -1(4-k)

-18 = k-4

k=-14



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