Question 965212
The square term needed is {{{(12/2)^2=36}}}.


{{{y=x^2+12x+36-3-36}}}
and you want to convert to a form,
{{{y=(x-h)^2+k}}}.


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