I am getting 7 as the value of b. I do not believe 4 is a correct answer!
Here's why:
General equation of a circle in the xy plane

with
being the x,y coordinates of the center.
The center point can be determined from the two endpoints of the diameter because the line segment is horizontal, so we just find the center of the x coordinates of the two points:

and the radius r = diameter/2 = 8-(-2)/2 = 5
so we have

Given a point on the circle (0,b) with b>0:

Answer:The answer is 4/28 is greater.
Step-by-step explanation:
Parallel lines have the same slope but different y-intercepts. Which answer has the same slope as the one above? Hint: m is the slope (coefficient of x)