[tex]\displaystyle\bf\\\left \{ {{2x=2} \atop {x+y=8}} \right. \\\\\\\left \{ {{x=1} \atop {y=8-x}} \right. \\\\\\\left \{ {{x=1} \atop {y=8-1} \right. \\\\\\\left \{ {{x=1} \atop {y=7}} \right. \\\\\\Otvet \ : \ (1 \ ; \ 7)[/tex]