Find the equation of the circle concentric with the circle `2x^2+2y^2-8x+10y-39=0` and having its area ` 16pi sq.units`

Find the equation of the circle concentric with the circle x^2 + y^2 - 4x - 6y - 3 = 0 and which touches the y axis

The equation of circle concentric with circle x^2+y^2-6x+ 12y+ 15=0 and double its area is

The equation of the circle concentric with the circle x ^(2) + y^(2) -4x-6y =0 and passing through the point (-4,-5) is

The equation of the circle concentric with the circle x^2+y^2+8x+10y-7=0 and passing through the centre of the circle x^2+y^2-4x-6y=0 is

Find the equation of the circle of radius 5 units and concentric with the circle x^2+y^2-6x+4y+12=0

Find the equation of the tangent to the circle x^2+y^2-4x-6y-12=0 at (-1,-1)

Answer the following:Find the equation of the circle concentric with x^2+y^2-4x+6y=1 and having radius 4 units.

Find the equation of a tangent to the circle x^2+y^2-3x+2y=0 at origin.

The equation to the tangent to the circle x^2+y^2-x+3y=10 at (-2,1) is

Find the area of the circle x^2+y^2=25 .