Question

Помогите! Дам последние баллы!!!! Фигню не писать!!!!

Answer 1

Ответ:

Ответ : 8

$3(x - 5) + 2(y - 4) = - 20 \\ 2(x - 2.5) - 3y = - (x - y) \\ \\ 3x - 15 + 2y - 8 = - 20 \\ 2x - 5 - 3y = - x + y \\ \\ 3x + 2y = 3 \\ 3x - 4y = 5 \\ \\ - 3x + 4y = - 5 \\ 3x + 2y = 3 \\ \\ 6y = - 2 \\ y = - \frac{ 1}{3} \\ 3x + 2 \times ( - \frac{1}{3} ) = 3 \\ 3x = 3 + \frac{2}{3} \\ 3x = 3 \frac{2}{3} \\ x = \frac{11}{9} \\ \\ \\ - 9 \times ( \frac{11}{9} + ( - \frac{1}{3} )) = - 9 (\frac{11}{9} - \frac{3}{9} ) = - 9 \times \frac{8}{9} = - 8$