Answer:
(2,-4) is the center
Step-by-step explanation:
The standard form of a circle is [tex](x-h)^2+(y-k)^2=r^2[/tex] where (h,k) is the center and r is the radius.
So if you compare
[tex](x-h)^2+(y-k)^2=r^2[/tex]
and
[tex](x-2)^2+(y+4)^2=r^2[/tex],
you should see that
[tex]h=2[/tex]
[tex]-k=4[/tex] which implies [tex]k=-4[/tex]
[tex]r^2=6[/tex] which implies [tex]r=\sqrt{6}[/tex].
So the center is (h,k)=(2,-4).
The radius is [tex]\sqrt{6}[/tex].