Prove that the centres of the circles `x^2+y^2=1`, `x^2+y^2+6x-2y-1=0` and `x^2+y^2-12x+4y=1` are collinear

Prove that the radi of the circles x^(2)+y^(2)=1x^(2)+y^(2)-2x-6y=6 and x^(2)+y^(2)-4x-12y=9 are in arithmetic progression.

Prove that the radii of the circles x^(2)+y^(2)=1,x^(2)+y^(2)-2x-6y=6and x^(2)+y^(2)-4x-12y-9=0 are in arithmetic progression.

The centres of the circles x ^(2) + y ^(2) =1, x ^(2) + y^(2)+ 6x - 2y =1 and x ^(2) + y^(2) -12 x + 4y =1 are

Prove that the radii of the circles x^(2)+y^(2)=1,x^(2)+y^(2)-2x-6y=6andx^(2)+y^(2)-4x-12y=9 are in AP.

Prove that the centres of the three circles x^(2)+y^(2)-4x6y12=0,x^(2)+y^(2)+2x+4y-5=0 and x^(2)+y^(2)-10x16y+7=0 are collinear.

The circles x^(2)+y^(2)-2x-4y+1=0 and x^(2)+y^(2)+4y-1 =0

Radii of circles x^(2) + y^(2) = 1, x^(2) + y^(2) - 2x - 6y= 6 and x^(2) + y^(2) - 4x - 12y = 9 are in