$\begin{array}{l}
3 x+5 y+\lambda z=3 \
7 x+11 y-9 z=2 \
97 x+155 y-189 z=\mu \
93 x+155 y+31 \lambda z=93 \
97 x+155 y-189 z=\mu \
-\quad+\quad+\quad- \
\hline-4 x+(31 \lambda+189) z=93-\mu \
1085 x+1705 y-1395 z=310 \
1067 x+1705 y-2079 z=11 \mu \
-\quad+\quad-\quad \
\hline 18 x+684 z=310-11 \mu
\end{array}\begin{aligned}
& -36 x+9(31 \lambda+189) z=9(93-\mu) \
& 36 x+1368 z=2(310-11 \mu) \
& (279 \lambda+3069) z=1457-31 \mu
\end{aligned}forinfinitesolutions−\begin{aligned}
& \lambda=\frac{-3069}{279}=\frac{-341}{31} \
& \mu=\frac{1457}{31}
\end{aligned}\mu+2 \lambda=\frac{1457-682}{31}=\frac{775}{31}=25$