<<VilGebra`

anchoventana=15;
ContourPlot[x^2+y^2+10 y==6 x+15,{x,-anchoventana,anchoventana},{y,-anchoventana,anchoventana},Axes->True,AxesOrigin->{0,0},AxesLabel->{"x","y"},PlotRange->{{-anchoventana,anchoventana},{-anchoventana,anchoventana}},Frame->False]