Respuesta :
Completing the square:
x^2 - 18x + y^2 + 8y = -5
x^2-18x +81 - 81 + y^2 + 8y + 16 - 16 = -5.
Then, (x-9)^2 + (y+4)^2 = -5 + 81 + 16 = 92
Then the desired equation is (x-9)^2 + (y+4)^2 = 92.
x^2 - 18x + y^2 + 8y = -5
x^2-18x +81 - 81 + y^2 + 8y + 16 - 16 = -5.
Then, (x-9)^2 + (y+4)^2 = -5 + 81 + 16 = 92
Then the desired equation is (x-9)^2 + (y+4)^2 = 92.