Question

{y-xy+3x=-3
{2y+xy-x=2

Answer 1

Прибавим первое уравнение ко второму:
3y + 2x = -1
y=(-1-2x)/3

$\frac{ - 1 - 2x}{3} - x \times \frac{1 - 2x}{3} + 3x = 0$
$\frac{ - 1 - 2x - x + 2 {x}^{2} + 9x }{3} = - 3$
$2 {x}^{2} + 6x + 8 = 0$

${x}^{2} + 3x + 4 = 0$
x1 = -4 y=(-1 -2*(-4))/3 = 7/3
x2 = 1, y=(-1-2*1)/3 = -1