Question 919630
{{{x^2+6x+y^2+10y+18=0}}}
{{{(x^2+6x)+(y^2+10y)+18=0}}}
You need to complete-the-square for the x and the y, before converting the equation into the standard form for a circle.


See this: <a href="http://www.algebra.com/my/Completing-the-Square-to-Solve-General-Quadratic-Equation.lesson?content_action=show_dev">http://www.algebra.com/my/Completing-the-Square-to-Solve-General-Quadratic-Equation.lesson?content_action=show_dev</a>


{{{highlight((x+3)^2+(y+5)^2=16)}}}


{{{graph(350,350,-10,1,-10,1,-5-sqrt(16-(x+3)^2),-5+sqrt(16-(x+3)^2))}}}