1. The problem statement, all variables and given/known data Show that the centers of the circles passing through the points (3,2) and (6,3) are located on the line 3x+y=16. Two of these circles touch the line x+2y=2. Find the equation of both these circles. 2. Relevant equations The general equation of curves (circles, parabola, ellipse, hyperbola) 3. The attempt at a solution The proving section is fine to me, I merely need to find the perpendicular bisector. I approached the question by trying to search for the centers of the circles. I expected myself to come to a linear equation and a quadratic equation (since there is two circles) One equation is clear : 3x+y=16 But I can't find the other one. Should I deal with the gradients? Or the radius of the circles?