Graph the circle expr(["+", X2T, Y2T])
                    = R * R.
                
                        The equation of a circle with center
                        (\blue{h}, \green{k}) and radius
                        \pink{r} is
                        (x - \blue{h})^2 + (y - \green{k})^2 =
                        \pink{r}^2.
                    
                        We can rewrite the given equation as
                        (x - \blue{negParens(H)})^2 + (y -
                        \green{negParens(K)})^2 =
                        \pink{R}^2.
                    
                            Thus, the center of the circle should be
                            (\blue{H}, \green{K})
                             and the radius should be
                            \pink{R}.