Respuesta :
[tex]{x}^{2} + {y}^{2} - 4x + 2y - 31 = 0 \\ {x}^{2} + {y}^{2} - 4x + 2y = 31 \\ ({x}^{2} - 4x + 4) +( {y}^{2} +2y + 1) = 31 + 4 + 1 \\ {(x - 2)}^{2} + {(y + 1)}^{2} = 36 = {6}^{2} [/tex]
so from the equation
center ( 2 , -1 )
radius 6
[tex]{x}^{2} + {y}^{2} - 4x + 2y - 31 = 0 \\ {x}^{2} + {y}^{2} - 4x + 2y = 31 \\ ({x}^{2} - 4x + 4) +( {y}^{2} +2y + 1) = 31 + 4 + 1 \\ {(x - 2)}^{2} + {(y + 1)}^{2} = 36 = {6}^{2} [/tex]
so from the equation
center ( 2 , -1 )
radius 6