Question

решите системы уравнений​

Answer 1

$3)3x - 5y = 23 : : | times 2 \ 2x + 3y = 9 : : | times ( - 3) \ \ 6x - 10y = 46 \ - 6x -9 y = - 27$

Складываем

$- 19y = 19 \ y = 9 div ( - 19) \ y = - 1$

$2x + 3y = 9 \ 2x + 3 times ( - 1) = 9 \ 2x - 3 = 9 \ 2x = 9 + 3 \ 2x = 12 \ x = 12 div 2 \ x = 6$

Ответ : (6 ; -1)

$4)6x + 5y = 0 \ 2x + 3y = - 8 : : | times ( - 3) \ \ 6x + 5y = 0 \ - 6x - 9y = 24$

Складываем

$- 4y = 24 \ y = 24 div ( - 4) \y = - 6$

$2x + 3y = - 8 \ 2x + 3 times - 6 = - 8 \ 2x - 18 = - 8 \ 2x = - 8 + 18 \ 2x = 10 \ x = 10 div 2 \ x = 5$

Ответ: (5 ; -6)