If the circle $x^2 + y^2 + 4x + 22y + c = 0$ bisects the circumference of the circle $x^2 + y^2 - 2x + 8y - d = 0$,then $c + d = . . . . .$

The radical centre of the circles $x^2+y^2+2x+3y+1=0$,$x^2+y^2+x-y+3=0$,and $x^2+y^2-3x+2y+5=0$ is

$x^2+y^2+2x+4y-20=0$ and $x^2+y^2+6x-8y+10=0$ are the given circles. Which one of the following is correct?

Find the equation of a circle with center $(4, 3)$ that touches the circle $x^2 + y^2 = 1$ internally.

If $A$ and $B$ are the centres of similitude with respect to the circles $x^2+y^2-14x+6y+33=0$ and $x^2+y^2+30x-2y+1=0$,then the midpoint of $AB$ is

If the lengths of the tangents drawn from a point $P$ to the circles $x^2+y^2-8x+40=0$,$5x^2+5y^2-25x+80=0$,and $x^2+y^2-8x+16y+160=0$ are equal,then the coordinates of point $P$ are: