Find the center of the circle x2+y2−6x+4y−23=0.
What is the slope of a chord centered at (3, 2) in the circle x2 + y2 = 25
If (-3, 2) lies on the circle x2+y2+2gx+2fy+c=0 which is concentric with the circle x2+y2+6x+8y−5=0, then c=