Where The Picture. ? Or Whole Problem
        
                    
             
        
        
        
Answer:
B, 4
Step-by-step explanation:
To do this you can use the Pathagaryos thereom a^2+b^2=c^2
So we have (x-2)^2+x^2=20
We can expand (x-2)^2 and get 
x^2-4x+4
so we have x^2 -4x +4 + x^2=20
We can combine like terms and subtract 20 from both sides to get
2x^2-4x-16=0
We can factor this and get (2x+4)(x-4)
which means that x=4 and -2
Obviously the length can't be a negative and so we reject x= -2 and we get x=4
We can double check it and see that 
(4-2)^2+4^2=20
and it does
 
        
             
        
        
        
The longest chord on the circle is the diameter, and the center of the circle is the midpoint of the diameter.
Use the midpoint formula to find the center
((x1 +x2)/2 , (y1+y2)/2).. Just substitute them for the solution
the x-coordinates are the same, so you can just subtract the y-coordinates to find the radius. 
10.5 - 8 = 2.5
The equation of the circle is (x - h)² + (y - k)² = r² where r is the radius and (h, k) is the center.
(x - 4)² + (y - 8)² = 6.25
        
                    
             
        
        
        
Answer:
makes no sense
Step-by-step explanation: