Question 969280
{{{x^2-12x+y^2+18y=4}}}
{{{(x^2-12x+36)+(y^2+18y+81)=4+36+81}}}
{{{(x-6)^2+(y+9)^2=121}}}
{{{(x-6)^2+(y+9)^2=11^2}}}