Ta có: $x=180^{\circ}-100^{\circ}=80^{\circ}$;
$y=180^{\circ}-x-50^{\circ}=180^{\circ}-80^{\circ}-50^{\circ}=50^{\circ}$.
Ta có: $x=180^{\circ}-100^{\circ}=80^{\circ}$;
$y=180^{\circ}-x-50^{\circ}=180^{\circ}-80^{\circ}-50^{\circ}=50^{\circ}$.