0 is the answer to the question.
Answer:
8.5
Step-by-step explanation:
slope of the line that contains KL
(y2 - y1)/(x2-x1)
(0-1)/(7-3)
m = -1/4
slope of the line that contains JK
(5-1)/(4-3)
m = 4
the linea are perpendicular so triangle is right
area = (leg1 x leg2)/2
KL = 
KJ = 
area = (√17)^2/2 = 17/2 = 8.5
Factors of -8 that add up to 2: 4 & -2
(x + 4)(x - 2)
Set x to 0 for both and solve
x = -4
x = 2