Question 1071227
Equation looks like a circle.  Why expect a vertex?


{{{x^2-4x+y^2+10y+13=0}}}
{{{x^2-4x+4+y^2+10y+25=-13+4+25}}}
{{{highlight((x-2)^2+(y+5)^2=16)}}}


No vertex, but CENTER (2,-5) and size of radius {{{sqrt(16)=4}}}.