Question 312994
Complete the square in x and y.
{{{x^2+6x+y^2-2y=90}}}
{{{(x^2+6x+9)+(y^2-2y+1)=90+1+9}}}
{{{(x+3)^2+(y-1)^2=100}}}
Compare to the equation of a circle centered at (h,k) with radius R,
{{{(x-h)^2+(y-k)^2=R^2}}}

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Center:(-3,1)
Radius 10