Answer :

[tex]\begin{gathered} -20=-4x-6x \\ -20=-10x \\ x=\frac{-20}{-10} \\ x=2 \end{gathered}[/tex]

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[tex]\begin{gathered} 6=1-2n+5 \\ 2n=1+5-6 \\ 2n=0 \\ n=\frac{0}{2} \\ n=0 \end{gathered}[/tex]