Answer:
r = [tex]\sqrt{7}[/tex], centre = (6, - 4 )
Step-by-step explanation:
The equation of a circle in standard form is
(x - h)² + (y - k)² = r²
with (h, k) the coordinates of the centre and r the radius
(x - 6)² + (y + 4)² = 7 ← is in standard form
with centre = (6, - 4) and r² = 7 , hence r = [tex]\sqrt{7[/tex]