Prove that the centres of the three circles = 0,x^2+y^2 + 2x + 4y -5 = 0 and x^2 + y^2 - 10x – 16y +7 = 0` are collinear.

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.

Two circles x^(2) + y^(2) - 2x - 4y = 0 and x^(2) + y^(2) - 8y - 4 = 0

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

Find the centre and radius of the circle x^(2)+y^(2)+2x-4y-4=0

Equation of radical axis of the circles x^(2) + y^(2) - 3x - 4y + 5 = 0 and 2x^(2) + 2y^(2) - 10x - 12y + 12 = 0 is

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

The locus of the centers of the circles which cut the circles x^(2) + y^(2) + 4x – 6y + 9 = 0 and x^(2) + y^(2) – 5x + 4y – 2 = 0 orthogonally is

Let circle cuts ortholognally each of the three circles x^(2) + y^(2) + 3x + 4y + 11 = 0, x^(2) + y^(2) - 3x + 7y - 1 = 0 and x^(2) + y^(2) + 2x = 0

The radical centre of three circles : x^2 + y^2 + x + 2y + 3 = 0, x^2 + y^2 + 2x + 4y + 5 = 0 and x^2 + y^2 - 7x - 8y - 9 = 0 is : (A) (- 2/3, - 2/3) (B) (1/3, 1/3) (C) (1/4, 1/4) (D) (0, 0)