Question

Determine o conjunto solução da equação: 


obs: gente me ajudem, é matéria de prova, socorro Jesus...​

Answer 1

$\boxed{\begin{array}{l}\rm Determine~a~soluc_{\!\!,}\tilde ao~da~equac_{\!\!,}\tilde ao:\\\begin{vmatrix}2&\sf x&\sf x\\\sf1&\sf2&\sf1\\\sf3&\sf1&\sf2\end{vmatrix}=12\\\tt a)\dfrac{3}{2}\\\\\tt b)-\dfrac{3}{2}\\\\\tt c)\dfrac{1}{2}\\\\\tt d)-\dfrac{1}{2}\end{array}}$

$\boxed{\begin{array}{l}\underline{\rm soluc_{\!\!,}\tilde ao:}\\\sf 2(4-1)-x(2-3)+x(1-6)=12\\\sf6+x-5x=12\\\sf 5x-x=6-12\\\sf 4x=-6\\\sf x=-\dfrac{6\div2}{4\div2}\\\\\sf x=-\dfrac{3}{2}\\\huge\boxed{\boxed{\boxed{\boxed{\sf\maltese~alternativa~b}}}}\end{array}}$