Answer:
-8, 4, 2
Step-by-step explanation:
x^2 + y^2 + 16x - 8y + 76 = 0
x^2 + y^2 + 16x - 8y = -76
x^2 + 16x + y^2 - 8y = -76
x^2 + 16x + ? + y^2 - 8y = -76 + ?
x^2 + 16x + 64 + y^2 - 8y = -76 + 64
(x + 8)^2 + y^2 - 8y = -12
(x + 8)^2 + y^2 - 8y + ? = -12 + ?
(x + 8)^2 + y^2 - 8y + 16 = -12 + 16
(x + 8)^2 + (y - 4)^2 = 4
(x + (-8))^2 + (y - 4)^2 = 2^2
