- #1

- 3,269

- 5

$\begin{array}{rll}

\textsf{rewrite} &(x^2+6x )+(y^2+8y)=-9\\

\textsf{complete square} &(x^2+6x+9)+(y^2+8y+16)=-9+9+16\\

\textsf{simplify equation} &(x+3)^2+(y+4)^2=16=4^2\\

\textsf{observation} &C(-3,-4), \quad R=4

\end{array}$

hopefully ok

is there another way to do this other than complete the square

if you are inclined to do so I would be interested in a tikz code would be fore this :unsure: