Equation of line
$\frac{x+1}{3}=\frac{y-9}{-4}=\frac{z+16}{12}$
G.P on line $(3 \lambda-1,-4 \lambda+9,12 \lambda-16)$
point of intersection of line \& plane
$6 \lambda-2-12 \lambda+27-12 \lambda+16=5$
$\lambda=2$
Point $(5,1,8)$
Distance $=\sqrt{36+64+576}=26$