Equation of given circles S1:x2+y2−4x−6y+5=0 S2:x2+y2−2x−4y−1=0 and ‌‌S3:x2+y2−6x−2y=0 ∴ Radical axis of circles S1 and S2 is 2x+2y−6=0⇒x+y=3.....(i) Similarly, the radical axis of circles S2 and S3 is −4x+2y+1=0 ....(ii) ∵ Radical centre is point of concurrency of radical axes, from radical axes Eqs. (i) and (ii), we get y=‌