1) show that the equation x² - 4x + y² +12y=9² representS a circle, and find its center (a, b) and r. and + radius 2) Sketch the circle from Problem D and label its center and Four Points on the circle along with their coordinates. 3) Using ( and @ shade the region in the plane represented by the inequality for the circumference, use x² - 4x + y² +12 Y>9. either a solid or a dashed ine, as appropriate.