Question

$\left \{ {{2x+y=1} \atop {2x-y=1}} \right.$

Answer 1

$\left \{ {{2x+y=1} \atop {2x-y=1}} \right. |+ \left \{ {{2x=2} \atop {2x-y=1}} \right. \left \{ {{x=1} \atop {1-y=1}} \right. \left \{ {{x=1} \atop {y=0}} \right.$
Ответ: $(1;0)$