С сегодняшнего дня я буду писать на русском
\(5:\left\{{}\begin{matrix}mx+y=-1\\x+y=-m\end{matrix}\right.\)\(\Leftrightarrow mx-x=m-1\)
\(\Leftrightarrow x\left(m-1\right)=m-1\Leftrightarrow x=1\left(m\ne1\right)\)
\(\Rightarrow x=y^2\Rightarrow x=y=1\)
\(\Rightarrow\left\{{}\begin{matrix}m+1=-1\\-m=2\end{matrix}\right.\)\(\Rightarrow m=-2\left(tm\right)\)
\(6;\left\{{}\begin{matrix}mx+2y=18\\x-y=-6\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}2m+2y=18\\2-y=-6\end{matrix}\right.\)\(\Leftrightarrow\left\{{}\begin{matrix}2m+2.8=18\\y=8\end{matrix}\right.\)\(\Leftrightarrow m=1\)
\(b,\Rightarrow mx+2x=6\Leftrightarrow x\left(m+2\right)=6\Leftrightarrow x=\dfrac{6}{m+2}\left(m\ne-2\right)\)
\(\Rightarrow\dfrac{6}{m+2}-y=-6\Rightarrow y=6+\dfrac{6}{m+2}\)
\(\Rightarrow2x+y=9\Leftrightarrow\dfrac{12}{m+2}+6+\dfrac{6}{m+2}=9\Rightarrow m=4\left(tm\right)\)
