Respuesta :

hello : 
x2 + y2 − 6x + 12y − 19 = 0
(x²-6x)+ (y²+12y) -19 = 0
(x²-6x+9)-9 + (y²+12y+36)-36 -19 = 0
(x-3)² + (y+6)² = 8²
the center is : (3 , -6) and radius : 8