You can put this solution on YOUR website! Determine the equation of the circle passing through A(-1,2) and B(4,7) and with center x-4=0
---------
If you mean the center is on the line x-4 = 0:
----------------
Find the perpendicular bisector of AB.
The center is the intersection of the PB and x = 4.
The radius is the distance from the center to either point.