Question

Me ajudem, por favor!
Ensino Fundamental II (8°ano)
Matemática

Answer 1

z = 180 -80 => z = 100º
$\frac{x}{2}+\frac{13y}{4}$ = 80 = $2x+y$ 
$- \left \{ {{2x+13y=320} \atop {2x+y=80}} \right.$ => $12y=240$ => $y=\frac{240}{12}$ => y = 20.
2x +y = 80 => 2x +20 = 80 => 2x = 80 -20 => 2x = 60 => $x = \frac{60}{2}$ => x = 30.