Verified answer

[tex]\displaystyle\bf\\\left \{ {{x-2y=5} \atop {x+y=-1 \ |\cdot 2}} \right. \\\\\\+\left \{ {x-2{y=5} \atop {2x+2y=-2}} \right.\\ ---------\\3x=3\\\\x=3:3=1\\\\y=-x-1=-1-1=-2\\\\\\Otvet \ : \ (1 \ ; \ -2)[/tex]