Resposta :
[tex]\Large\boxed{\begin{array}{l}\sf\,21|\underline{6~~~~~~~~}\\\underline{\sf\!\!\!\!\!-18}~\sf3,5\\\sf30\\\underline{\!\!\!\!\sf-30}\\\sf~0~\\\\\sf \dfrac{21}{6}=3,5\end{array}}[/tex]
[tex]\Large\boxed{\begin{array}{l}\sf\,21|\underline{6~~~~~~~~}\\\underline{\sf\!\!\!\!\!-18}~\sf3,5\\\sf30\\\underline{\!\!\!\!\sf-30}\\\sf~0~\\\\\sf \dfrac{21}{6}=3,5\end{array}}[/tex]