Question

срочно надо решения примера снизу!!!

Answer 1

1)

$- 4x +9 y = 4 \\ 4x - 5y = 12 \\ \\ 4x - 4x +9 y - 5y = 12 + 4 \\ 4y =1 6 \\ y = 16 \div 4 \\ y = 4 \\ \\ 4x - 5 \times 4 = 12 \\ 4x - 20 = 12 \\ 4x = 12 + 20 \\ 4x = 32 \\ x = 32 \div4 \\ x = 8$

Ответ: ( 8 ; 4 )

2)

$x + 3y = - 7 \: \: | \times ( - 2) \\ 2x + 15y = - 10 \\ \\ - 2x - 6y = 14 \\ 2x + 15y = - 10 \\ 2x - 2x + 15y - 6y = 14 - 10 \\ 9y = 4 \\ y = \frac{4}{9} \\ \\ x + 3 \times \frac{4}{9} = - 7 \\ x + \frac{4}{3} = - 7 \\ x = - 7 - 1 \frac{1}{3} \\ x = - 8 \frac{1}{3}$

Ответ: ( - 8 1/3 ; 4/9 )