Respuesta :

[tex]\bf \cfrac{1}{3}m=12-m\impliedby \textit{now, if we multiply both sides by }3 \\\\\\ \boxed{3}\cdot \cfrac{1}{3}m=\boxed{3}\cdot 12-\boxed{3}\cdot m\implies m=36-3m\implies 4m=36 \\\\\\ m=\cfrac{36}{4}\implies m=9[/tex]