Question

qual é a resposta de {x+y=4 {x-y=8

Answer 1

$\large\bm{\begin{cases}x + y = 4 \\ x - y = 8\end{cases}} \\\\ \large\bm{\begin{cases}x + y = 4 \\ x = 8 + y\end{cases}} \\\\\large\bm{8 + y + y = 4} \\\\ \large\bm{8 + 2y = 4} \\\large\bm{2y = 4 - 8} \\\large\bm{2y = - 4} \\\large\bm{y = - 2} \\ \\ \large\bm{x = 8 +\left( - 2\right) } \\\\\large\bm{x = 8 - 2} \\\large\bm{x = 6} \\\large\bm{\left(x,y\right) = \left(6, - 2\right)} \\ \\ \large\bm{\begin{cases}6 +\left( - 2\right) = 4 \\ 6 - \left( - 2\right) = 8 \end{cases}} \\\\ \large\bm{\begin{cases}4 = 4 \\ 8 = 8\end{cases}} \\\\ \large\bm{}\bm{\large\boxed{\boxed{  { \large \bm{ \left(x,y\right) = \left(6, - 2\right) }}}}}$

${\large\boxed{\boxed{  { \large \bm{ Bons~Estudos} }}}}$