Question

Помогите решить уравнение,пж.Даю 23б x+y=180 x-y=130

Answer 1

$\left \{ {{x+y=180} \atop {x-y=130}} \right. \\ \left \{ {{x=180-y} \atop {180-y-y=130}} \right. \\ \left \{ {{x=180-y} \atop {180-2y=130}} \right. \\ \left \{ {{x=180-y} \atop {-2y=130-180}} \right. \\ \left \{ {{x=180-y} \atop {-2y=-50}} \right. \\ \left \{ {{x=180-y} \atop {y=25}} \right. \\ \left \{ {{x=180-25} \atop {y=25}} \right. \\ \left \{ {{x=155} \atop {y=25}} \right.$