If $(x, y, z)$ be an arbitrary point lying on a plane $P$ which passes through the point $(42,0,0),(0,42,0)$ and ( $0,0,42$ ), then the value of expression
$$
\begin{aligned}
3+\frac{x-11}{(y-19)^2(z-12)^2} & +\frac{y-19}{(x-11)^2(z-12)^2} \\
& +\frac{z-12}{(x-11)^2(y-19)^2}-\frac{x+y+z}{14(x-11)(y-19)(z-12)}
\end{aligned}
$$
