[tex]\boxed{\begin{array}{l}\underline{\rm 1^a\,forma\,de\,resolver:}\\\sf -8-x=2+2x\\\sf usando\,o\,princ\acute ipio\,aditivo,subtraia\,2x\,nos\,dois\,membros.\\\sf -8-x-\underline{2x}=2+2x-\underline{2x}\\\sf -8-3x=2\\\sf usando\,o\,princ\acute ipio\,aditivo,adicione\,8\,aos\,dois\,membros.\\\sf -8+\underline{8}-3x=2+\underline{8}\\\sf -3x=10\\\sf use\,o\,princ\acute ipio\,multiplicativo\,e\\\sf multiplique\,os\,dois\,membros\,por\,-1.\\\sf -3x\cdot\underline{(-1)}=10\cdot\underline{(-1)}\end{array}}[/tex]
[tex]\large\boxed{\begin{array}{l}\sf3x=-10\\\sf usando\,o\,princ\acute ipio\,multiplicativo\\\sf divida\,os\,dois\,membros\,por\,3.\\\sf \dfrac{3x}{\bf3}=\dfrac{-10}{\bf3}\\\\\sf x=-\dfrac{10}{3}\end{array}}[/tex]
[tex]\boxed{\begin{array}{l}\underline{\rm 2^a\,forma\,de\,resolver:}\\\sf Procure\,deixar\,as\,letras\,e\,os\,n\acute umeros\,com\,letras\\\sf no\,membro\,esquerdo~desfazendo\,a\,operac_{\!\!,}\tilde ao\\\sf matem\acute atica\,quando\,necess\acute ario.\\\sf Analogamente,procure~deixar~os~n\acute umeros\\\sf no~membro\,direito\,desfazendo\,a\,operac_{\!\!,}\tilde ao\,matem\acute atica\\\sf quando\,necess\acute ario.\end{array}}[/tex]
[tex]\large\boxed{\begin{array}{l}\sf-8-x=2+2x\\\sf -x-2x=2+8\\\sf-3x=10\cdot(-1)\\\sf 3x=-10\\\sf x=-\dfrac{10}{3}\end{array}}[/tex]
