Answer:
x^2-18x+y^2+18y+137=0
express both x and y term in completed square form
(x-9)^2 -81+(y+9)^2-81+137=0
(x-9)^2+(y+9)^2-25=0
(x-9)^2+(y+9)^2=5^2
here the x coordinate of the centre is +9
y coordinate is -9(the negative value of the value associated with the x and y square brackets)
radius=5
