Answer:
its number 6
Step-by-step explanation:
 
        
             
        
        
        
The slope of the line between the points On the line would be -1. And the y intercept would be 1. 
Y = -x + 1.
        
             
        
        
        
Answer:
K(-4,8) is the ortho center.
Step-by-step explanation:
In a right angled triangle, The vertex of the right angle is the ortho center. 
Here we are given 
J(-4,-1), K(-4,8) & L(2,8)
Using distance formula we get



So we can say that

By converse of pythagorean theorem we get

Hence the Vertex of the right angle is K(-4,8)
K(-4,8) is the ortho center.