Show that two tangents can be drawn from the point $\left(9, 0\right)$ to the circle $x^2+y^2-16=0$ , also find the equation of the pair of tangents and the angle between them.

 If the length of the tangent from $\left(f,g\right)$ to the circle $x^2+y^2=6$ be twice the length of the tangent from $\left(f,g\right)$ to the circle $x^2+y^2+3x+3y=0$, then will $f^2+g^2+4f+4g+2=0?$