Verified answer

[tex]\displaystyle\bf\\\left \{ {{x - 2y = 5} \atop {x + y = - 1 \: \: | \times 2}} \right. \\ \displaystyle\bf\\ + \left \{ {{x - 2y = 5} \atop {2x + 2y = - 2 }} \right. \\ \\ x + 2x = 5 - 2 \\ 3x = 3 \\ x = 3 \div 3 \\ x = 1 \\ \\ 1 + y = - 1 \\ y = - 1 - 1 \\ y = - 2[/tex]

Ответ: ( 1 ; - 2 )