Question

Нужно только 5
Срочно!!!!!!!

Answer 1

{xy = -12

{x + y = 4

x = 4 - y

(4 - y)×y = -12

4y - y² = -12

-y² + 4y + 12 = 0 |×(-1)

y² - 4y - 12 = 0

За теоремою Вієта:

{y1 + y2 = 4

{y1 × y2 = -12

y1 = -2; y2 = 6

x1 = 4 + 2 = 6

x2 = 4 - 6 = -2

{x1 = 6, x2 = -2

{y1 = -2, y2 = 6