
Line : −8x+6=12y−7=−16z+5 $\begin{aligned}
& \frac{\mathrm{x}+6}{2}=\frac{\mathrm{y}-7}{-3}=\frac{\mathrm{z}+5}{4}=\lambda \
& \mathrm{Q}(2 \lambda-6,7-3 \lambda, 4 \lambda-5) \
& \overline{\mathrm{QR}}(2 \lambda-7,-3 \lambda, 4 \lambda-11) \
& \overline{\mathrm{QR}} \cdot \text { dr's of line }=0 \
& 4 \lambda-14+9 \lambda+16 \lambda-44=0 \
& 29 \lambda=58 \Rightarrow \lambda=2 \
& \mathrm{Q}(-2,1,3) \
& \mathrm{PQ}=\sqrt{144+9+16}=\sqrt{169}=13
\end{aligned}$