`x^(2) + y^(2) = 144 and x^(2) + y^(2) - 15x + 11y = 0`
Find the radical axis of the pairs of circles

Find the equation of a circle which is co-axial with the circles x^(2)+y^(2)+4x+2y+1=0andx^(2)+y^(2)-x+3y-(3)/(2)=0 and having its centre on the radical axis of these circles.

Find the equation of the system of circles co-axial with the circles x^(2)+y^(2)+4x+2y+1=0andx^(2)+y^(2)-2x+6y-6=0 Also, find the equation of that particular circle whose cneter lies on the radical axis.

(i) 12x^(2) + 11x + 2 = 0 (ii) 25y^(2) + 15y+2 = 0

I. 3x^(2) - 7x+2 = 0" " II. 2y^(2) - 11y + 15 = 0

I. x^(2)+8x+15 = 0 II. y^(2) + 11y + 30 = 0

(i) Find the equation of a circle , which is concentric with the circle x^(2) + y^(2) - 6x + 12y + 15 = 0 and of double its radius. (ii) Find the equation of a circle , which is concentric with the circle x^(2) + y^(2) - 2x - 4y + 1 = 0 and whose radius is 5. (iii) Find the equation of the cricle concentric with x^(2) + y^(2) - 4x - 6y - 3 = 0 and which touches the y-axis. (iv) find the equation of a circle passing through the centre of the circle x^(2) + y^(2) + 8x + 10y - 7 = 0 and concentric with the circle 2x^(2) + 2y^(2) - 8x - 12y - 9 = 0 . (v) Find the equation of the circle concentric with the circle x^(2) + y^(2) + 4x - 8y - 6 = 0 and having radius double of its radius.

The radical axis of the circles x^2 +y^2 +4x-6y=12 and x^2+y^2+2x-2y-1=0 divides the line segment joining the centres of the circles in the ratio

The circles whose equations are x^(2)+y^(2)+10x-2y+22=0 and x^(2)+y^(2)+2x-8y+8=0 touch each other. The circle which touch both circles at, the point of contact and passing through (0,0) is, 1) 9(x^(2)+y^(2))-15x-20y=0, 2) 5(x^(2)+y^(2))-18x-80y=0 3) 7(x^(2)+y^(2))-18x-80y=0, 4) x^(2)+y^(2)-9x-40y=0 ]]