Chapter 1, Equations and Graphs - Section 1.2 - Graphs of Equations in Two Variables; Circles - 1.2 Exercises - Page 103: 94

No graph

$x^2+y^2-16x+12y+200=0$ $x^2-16x+y^2+12y=-200$ (Add with $64$ and $36$ to complete the square) $x^2-16x+64+y^2+12y+36=-200+64+36$ $(x-8)^2+(y+6)^2=-100$ There is no point which satisfies the last equation. So, the graph of the equation is nothing.