Two circles `x^2 + y^2 + 2x-4y=0 and x^2 + y^2 - 8y - 4 = 0` (A) touch each other externally (B) intersect each other (C) touch each other internally (D) none of these

Two circles x^(2) + y^(2) -2kx = 0 and x^(2) + y^(2) - 4x + 8y + 16 = 0 touch each other externally.Then k is

Examine whether the two circles x^2+y^2-2x-4y=0 and x^2+y^2-8y-4=0 touch each other externally or internally .

Examine whether the two circles x^2+y^2-2x-4y=0 and x^2+y^2-8y-4=0 touch each other externally or internally .

Examine whether the circles x ^2 + y ^2 - 2x - 4y = 0 and x ^2 + y ^2 - 8y - 4 = 0 touch each other.

The circles x^(2)+y^(2)-12x-12y=0 and x^(2)+y^(2)+6x+6y=0:( a) intersect in two points.(b) touch each other externally.(c) touch each other internally.(d) None of these

If the circles x^(2) + y^(2) = a^(2) and x^(2) + y^(2) - 6x - 8y + 9 = 0 touches each other externally, then a = …….

If two circles and a(x^2 +y^2)+bx + cy =0 and p(x^2+y^2)+qx+ry= 0 touch each other, then

If circles x^(2) + y^(2) = 9 " and " x^(2) + y^(2) + 2ax + 2y + 1 = 0 touch each other , then a =