Find the equation of the circles whose radius is 4 and whish is concentric with the circle `x^(2)+y^(2)+2x-6y=0`

Find the equation of the circle whose radius is 5a n d which touches the circle x^2+y^2-2x-4y-20=0 externally at the point (5,5)dot

Centre of the circle whose radius is 3 and which touches internally the circle x^(2)+y^(2)-4x-6y-12=0 at the point (-1 -1) is

Find the equation of the circle passing throught (1,1) and the points of intersection of the circles x^(2)+y^(2)+13x-3y=0 and 2x^(2)+2y^(2)+4x-7y-25=0

Find the equation of the circle described on the chord 3x+y+5=0 of the circle x^(2)+y^(2)=16 as diameter.

Find the equation of tangent to the circle x^(2) + y^(2) + 2x -3y -8 = 0 at (2,3)

Difference in values of the radius of a circle whose center is at the origin and which touches the circle x^2+y^2-6x-8y+21=0 is_____________

Find the equation of the circle which cuts the three circles x^2+y^2-3x-6y+14=0,x^2+y^2-x-4y+8=0, and x^2+y^2+2x-6y+9=0 orthogonally.

Find the centre and the radius of the circle x^(2)+y^(2)+8x+10y-8=0 .

Find the equations of the circles passing through the point (-4,3) and touching the lines x+y=2 and x-y=2