Question

ПОМОГИТЕ ПОЖАЛУЙСТА!!!​

Answer 1

$\displaystyle\bf\\\left \{ {{x=6} \atop {21x-y=11}} \right. \\\\\\\left \{ {{x=6} \atop {y=21x-11}} \right. \\\\\\\left \{ {{x=6} \atop {y=21\cdot 6-11}} \right.\\\\\\\left \{ {{x=6} \atop {y=126-11}} \right. \\\\\\\left \{ {{x=6} \atop {y=115}} \right. \\\\\\Otvet: \ (6 \ ; \ 115)$