What is the center of the equation X^2+y^2-4x-8y-16=0

x² + y² - 4x - 8y - 16 = 0

+ 16 + 16

x² + y² - 4x - 8y = 16

x² - 4x + y² - 8y = 16

(x² - 4x + 4) + (y² - 8y + 16) = 16 + 4 + 16

(x² - 2x - 2x + 4) + (y² - 4y - 4y + 16) = 20 + 16

[x (x) - x (2) - 2 (x) - 2 (-2) ] + [y (y) - y (4) - 4 (y) - 4 (4) ] = 36

[x (x - 2) - 2 (x - 2) ] + [y (y - 4) - 4 (y - 4) ] = 36

(x - 2) (x - 2) + (y - 4) (y - 4) = 36

(x - 2) ² + (y - 4) ² = 36

36 36 36

¹/₃₆ (x - 2) ² + ¹/₃₆ (y - 4) ² = 1

Center: (2, 4)