This is 8). the line is 5 on the y-axis.
 
        
        
        
Answer:
40% OR -1/4
Step-by-step explanation:
It could be 40% as all the other numbers are in fraction form while this one is written as a percent. 
It could also be -1/4 because that is the only negative number.
 
        
                    
             
        
        
        
X = k x y
21 = k x 3
k = 7
x = 7y
x = 7(10)
x = 70
        
             
        
        
        
I think the correct answer is 17