Relax

Respuesta :

Nevens

[tex] {x}^{2} + 2x + {y }^{2} - 4y = 12 \\ ( {(x + 1)}^{2} - 1) + ( {(y - 2)}^{2} - 4) = 12 \\ {(x + 1) }^{2} + {(y - 2)}^{2} = 17 \\ so \: \: c \: ( - 1 \: \: 2)[/tex]