Prove that the circles `x^(2) + y^(2) + 4x - 10y - 20 = 0` and `x^(2) + y^(2) - 4x - 4y + 4 = 0` touch each other internally. Find the equation of their common tangent.

Show that the circles x^(2) + y^(2) + 6x + 14y + 9 = 0 and x^(2) + y^(2) - 4x - 10y - 7 = 0 touch each other externally, find also the equation of the common tangent of the two circles.

Show that the circles x^(2) +y^(2) - 2x - 4y - 20 = 0 and x^(2) + y^(2) + 6x +2y- 90=0 touch each other . Find the coordinates of the point of contact and the equation of the common tangent .

Show that the circles x^(2)+y^(2)-10x+4y-20=0 and x^(2)+y^(2)+14x-6y+22=0 touch each other.Find the coordinates of the point of contact and the equation of the common tangent at the point of contact.

Show that the circles x^2+y^2-10 x+4y-20=0 and x^2+y^2+14 x-6y+22=0 touch each other. Find the coordinates of the point of contact and the equation of the common tangent at the point of contact.

Show that the circles x^2+y^2-10 x+4y-20=0 and x^2+y^2+14 x-6y+22=0 touch each other. Find the coordinates of the point of contact and the equation of the common tangent at the point of contact.

Show that the circles x^2+y^2-10 x+4y-20=0 and x^2+y^2+14 x-6y+22=0 touch each other. Find the coordinates of the point of contact and the equation of the common tangent at the point of contact.

The number of common tangent to the circles x^(2) + y^(2) + 4x - 6y - 12 = 0 and x^(2) + y^(2) - 8x + 10y + 5 = 0 is

The circles x^2 +y^2=9 and x^2 +y^2-2y+27=0 touch each other. The equation of their common tangent is