
$\begin{aligned}
& \text { Dr's of } \mathrm{AC} \Rightarrow 2 \lambda, 3 \lambda-2,4 \lambda \
& \text { Dr's of } \mathrm{BC} \Rightarrow \mu+2,2 \mu+3, \mu-1 \
& \Rightarrow \frac{\mu+2}{2 \lambda}=\frac{2 \mu+3}{3 \lambda-2}=\frac{\mu-1}{4 \lambda} \
& \Rightarrow 2(\mu+2)=\mu-1 \Rightarrow \mu=-5 \
& \Rightarrow \text { Dr's of } \mathrm{BC} \Rightarrow 3,7,6 \
& \Rightarrow \text { equation of } \mathrm{L} \Rightarrow \frac{\mathrm{x}-1}{3}=\frac{\mathrm{y}-1}{7}=\frac{\mathrm{z}-1}{6}
\end{aligned}$
(7,15,13) satisfies.