[tex]\large\boxed{\begin{array}{l}\rm x\longrightarrow quantidade\,de\,quest\tilde oes\,certas\\\rm y\longrightarrow quantidade\,de\,ques\tilde oes\,erradas\\\begin{cases}\rm x+y=16\\\rm5x-y=38\end{cases}\\\\+\underline{\begin{cases}\rm -\diagdown\!\!\!\!\!\!5x-5y=-80\\\rm\diagdown\!\!\!\!\!\!5x-y=38\end{cases}}\\\rm -6y=-42\cdot(-1)\\\rm 6y=42\\\rm y=\dfrac{42}{6}\\\\\rm y=7\\\huge\boxed{\boxed{\boxed{\boxed{\rm\dagger\red{\maltese}~\blue{alternativa~d}}}}}\end{array}}[/tex]
