Respuesta :

sqdancefan
Add the squares of half the x- and y- coefficients after you put the constant on the right.
   (x² + 6x) + (y² + 4y) = -9
   (x² + 6x + 9) + (y² + 4y + 4) = -9 +9 +4
In standard form ...
   (x + 3)² + (y + 2)² = 4