Question

resolva o sistema : {X +2y=8 2x-y =17}

Answer 1

$\left \{ {{x+2y=8}(1) \atop {2x-y=17}(2)} \right.$
$\left \{ {{x+2y=8} \atop {4x-2y=34}} \right.$
5x = 42
  x = 42/5
  x = 8,4

8,4 + 2y = 8
2y = 8 - 8,4
2y = 0,4
  y = $\frac{2}{5} . \frac{1}{2}$
  y = 5