Question 973913
{{{x^2+y^2+2x+4y-31=0}}}
{{{x^2+2x+y^2+4y-31=0}}}
{{{x^2+2x+1+y^2+4y+4-31=1+4}}}
{{{(x+1)^2+(y+2)^2-31=5}}}
{{{highlight((x+1)^2+(y+2)^2=36)}}}