Answer:
x^2 + y^2 -2x -8y -47 =0
Step-by-step explanation:
The center is at (1,4) and the radius is 8 units
We can write the equation as
(x-h)^2 + (y-k)^2 = r^2
where (h,k) is the center and r is the radius
(x-1)^2 + (y-4)^2 = 8^2
Foil
x^2 -2x+1 + y^2 -8y +16 = 64
x^2 + y^2 -2x -8y +17 =64
Subtract 64 from each side
x^2 + y^2 -2x -8y +17-64 =64-64
x^2 + y^2 -2x -8y -47 =0
