The value of digit 5 in the number is tens of thousands. Thus, the value of the digit is;
50,000
So if you didn't know x^2 + y^2 = r^2 is the equation of a circle where the center is at the origin. It is usually written as (x-h)^2 + (y-k)^2 = r^2. So if we are moving it to the left by 8 units we write:
(x+8)^2 + (y-k)^2 = 16
Next we move it 3 units down, so we get:
(x+8)^2 + (y+3)^2 = 16
That is your answer. Hope this helps! :D
Can you show us the number line model?