Question 1085148
{{{x^2-5x+y^2+4y=16}}}
{{{x^2-5x+(5/2)^2+y^2+4y+4=(5/2)^2+4+16}}}
{{{(x-5/2)^2+(y+2)^2=25/4+20}}}
{{{(x-5/2)^2+(y+2)^2=105/4}}}


Center is  ( 5/2, -2 ) and radius is {{{(1/2)sqrt(105)}}}.
(Radius approx.  5.123 )