Возведя в квадрат
{x+3y+6=4
{2x-y+2=1
{x+3y=-2
{2x-y=-1
{2x+6y=-4
{2x-y=-1
отняв
{7y=-3
{y=-3/7
{x=-5/7
{y=-3/7
{y/x=3/5
(x - 4)(x + 2)(x + 8)(x + 14) = 1204
x² - 4x + 2x - 8 (x + 8)(x + 14) = 1204
x³ - 4x² + 2x² - 8x + 8x² - 32x + 16x - 64 (x + 14) = 1204
x^4 - 4x³ + 2x³ - 8x² + 8x³ - 32x² + 16x² - 64x + 14x³ - 56x² + 28x² - 112x + 112x² - 448x + 224x - 896 = 1204
x^4 + 20x³ + 44x² - 400x - 896 = 1204
x^4 + 20x³ + 44x² - 400x = 1204 + 896
x^4 + 20x³ + 44x² - 400x = 2100
4 - 15х - 12,5 = 3х + 9,5
-15х - 3х = - 4 +12,5 + 9,5
- 18х = 18
18х = - 18
х = -1