Question

Нужно решить срочно только 1261 первую и вторую систему

Answer 1

1)

$2x - 3y + 1 + (x - y + 5) = 0 \ 5x + 7y - (8x + y + 1) = 0 \ \ 2x - 3y + 1 + x - y + 5 = 0 \ 5x + 7y - 8x - y - 1 = 0 \ \ 3x - 4y + 6 = 0 \ - 3x + 6y - 1 = 0</p><p>$

Складываем

$2y + 5 = 0 \ 2y = - 5 \ y = - 5 div 2 \ y = - 2.5 \ \ 3x - 4y + 6 = 0 \ 3x - 4 times ( - 2.5) + 6 = 0 \ 3x + 10 + 6 = 0 \ 3x + 16 = 0 \ 3x = - 16 \ x = - 16 div 3 \ x = - 5 frac{1}{3} \ \ otvet : ( - 5 frac{1}{3} : ; : - 2.5)$

2)

$7x + 9y - 14 + y - 5x - 11 + 3 = 0 \ 11x + y - 9 + 4y - 9x - 7 = 0 \ \ 2x + 10y - 22 = 0 \ 2x + 5y - 16 = 0 : : | times ( - 1)\ \ 2x + 10y - 22 = 0 \ - 2x - 5y + 16 = 0$

Складываем

$5y - 6 = 0 \ 5y = 6 \ y = 6 div 5 \ y = 1.2 \ \ 2x + 10y - 22 = 0 \ 2x + 10 times 1.2 - 22 = 0 \ 2x + 12 - 22 = 0 \ 2x - 10 = 0 \ 2x = 10 \ x = 10 div 2 \ x = 5 \ \ otvet : (5 : ; : 1.2)$