Question

Помогите, долго мучаюсь

Answer 1

{3y^2 -xy = 20
{x = -2 -3y

3y^2 -(-2 -3y)y = 20

3y^2 -(-2y -3y^2) = 20

3y^2 +2y +3y^2 = 20

6y^2 +2y -20 = 0

3y^2 +y -10 = 0
D = 1 + 120 = 121
y = (-1-11)/6 = -2
y = (-1+11)/6 = 5/3

x + 3*(-2) = -2
x = 6 -2
x = 4

x + 3 * 5/3 = -2
x = -5 -2
x = -7

Ответ: (4; -2), (-7; 5/3).