If the length of the tangent from `(6,-7)` to the circle `3x^(2)+3y^(2)-kx-6y=12` is `9,` the value of `k` is

Length of tangent from (8,6) to the circle x^(2)+y^(2)-3x-4y+2=0

If the length of the tangent from (f,g) to the circle x^(2)+y^(2)=6 is twice the length of the tangent from the same point to the circle x^(2)+y^(2)+3x+3y=0 , then

The length of the tangent to the circle x^(2)+y^(2)-2x-y-7=0 from (-1, -3), is