Question

Решите систему управнений​

Answer 1

$x - 5y = 23 \: \: | \times 2 \\ 7x + 10y = - 19 \\ \\ 2x - 10y = 46 \\ 7x + 10y = - 19$

Складываем

$9x = 27 \\ x = 27 \div 9 \\ x = 3 \\ \\ x - 5y = 23 \\ 5y = x - 23 \\ 5y = 3 - 23 \\ 5y = - 20 \\ y = - 20 \div 5 \\ y = - 4$

Ответ: (3 ; -4)