Question

помогите пожалуйста!!!!!!!​

Answer 1

$\displaystyle\bf\\\left \{ {{x + y = 8} \atop {x - 3y = 4 \: \: | \times ( - 1) }} \right. \\ \displaystyle\bf\\ + \left \{ {{x + y = 8} \atop { - x + 3y = - 4 }} \right. \\ \\ 3y + y = 8 - 4 \\ 4y = 4 \\ y = 4 \div 4 \\ y = 1 \\ \\ x + 1 = 8 \\ x = 8 - 1 \\ x = 7$

Ответ: ( 7 ; 1 )