Question

пж 2x-7y=3
система 3x+4y=-10​

Answer 1

$2x - 7y = 3 \: \: | \times ( - 3)\\ 3x + 4y = - 10 \: \: | \times 2 \\ \\ - 6x + 21y = - 9 \\ 6x + 8y = - 20 \\ Складываем \\ 29y = - 29 \\ y = - 1 \\ \\ 2x - 7 \times ( - 1) = 3 \\ 2x + 7 = 3 \\ 2x = 3 - 7 \\ 2x = - 4 \\ x = - 4 \div 2 \\ x = - 2 \\ \\ Ответ: \: ( - 2 ; - 1)$