Answer:
centre = (- 2, 3 )
Explanation:
the equation of a circle in standard form is
(x - h)² + (y - k)² = r²
where (h, k ) are the coordinates of the centre and r is the radius
given
x² + y² + 4x - 6y = 12 ( collect x/ y terms )
x² + 4x + y² - 6y = 12
using the method of completing the square
add ( half the coefficient of the x/ y terms)² to both sides
x² + 2(2)x + 4 + y² + 2(- 3)y + 9 = 12 + 4 + 9
(x + 2)² + (y - 3)² = 25 ← in standard form
with centre (- 2, 3 ) and r =
= 5