Question

помогите решить пожалуйста!!

Answer 1

9)
$\frac{1}{5} (x + y) = 2 \\ \frac{1}{2} (x - y) = 1 \\ \\ x + y = 10 \\ x - y = 2 \\ \\ 2x = 12 \\ y = x - 2 \\ \\ x = 6 \\ y = x - 2 \\ \\ x = 6 \\ y = 4$
Ответ: (6; 4)

11)
$x + y = 1 - z \\ x - y = 3 \\ z = 2x \\ \\ z = 2x \\ x + y = 1 - 2x \\ x - y = 3 \\ \\ z = 2x \\ 3x + y = 1 \\ x - y = 3 \\ \\ z = 2x \\ 4x = 4 \\ y = x - 3 \\ \\ x = 1 \\ y = x - 3 \\ z = 2x \\ \\ x = 1 \\ y = - 2 \\ z = 2$
Ответ: (1; -2; 2)