Answer:
centre = (2, - 3 ) and radius = 5
Step-by-step 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 = 0 ( add 12 to both sides )
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 (h, k ) = ( 2, - 3 ) and r = = 5