Verified answer

xy(x + y) = 30

xy(x - y) = 6

x,y ≠ 0

Делим 1 на 2

(x + y)/(x - y) = 5

x + y = 5x - 5y

4x = 6y

x = 3/2y

3/2y*y(3/2y - y) = 6

3/4y³ = 6

y³ = 8

y = 2

x = 3/2y = 3