#### Answer

No graph.

#### Work Step by Step

We convert the equation to the circle formula by completing the square:
$x^2+y^2+72=12x$
$(x^2-12x)+y^2=-72$
$(x^2-12x+36)+y^2=-72+36$
$(x-6)^2+y^2=-36$
Since $r^2$ is negative this equation does not make sense and has no graph.