Resposta :
[tex]\begin{bmatrix}2x-y=12\\ y=2\end{bmatrix}\\\\\begin{bmatrix}2x-2=12\end{bmatrix}\\\\2x-2=12\\\\2x=14\\\\\frac{2x}{2}=\frac{14}{2}\\\\x=7\\\\x=7,\:y=2[/tex]
[tex]\begin{bmatrix}2x-y=12\\ y=2\end{bmatrix}\\\\\begin{bmatrix}2x-2=12\end{bmatrix}\\\\2x-2=12\\\\2x=14\\\\\frac{2x}{2}=\frac{14}{2}\\\\x=7\\\\x=7,\:y=2[/tex]