A \(=(-2,2,3)\), \(B=(13,-3,13)\) are two points and \(P\) is a variable point such that
\[
PA:PB=2:3.
\]
If \(P\) lies on the sphere
\[
x^2+y^2+z^2+ux+vy+wz-247=0,
\]
then
\[
u+v+w=
\]
Show Hint
For a fixed ratio
\[
PA:PB=m:n,
\]
use
\[
n^2PA^2=m^2PB^2.
\]
After expansion, the locus is always a sphere (Apollonius sphere). Compare coefficients directly with the given equation.