Question 1160439
x^2+6x+y^2-8y-11=0

{{{x^2+6x+y^2-8y=11}}}

{{{x^2+6x+9+y^2-8y+16=11+9+16}}}

{{{(x+3)^2+(y-4)^2=36}}}

{{{(x+3)^2+(y-4)^2=6^2}}}--------------------------This tells what you need.