(x^2 +2x)(x^2 + 2x - 2) = 3
x^2 + 2x - 1 = t
(t + 1)(t - 1) = 3
t^2 - 1 = 3
t^2 = 4
t = 2
t = -2
1. x^2 + 2x - 1 = 2
x^2 + 2x - 3 = 0
D = 4 + 12 = 16
x12 = (-2 +- 4)/2 = -3 1
2. x^2 + 2x - 1 = -2
x^2 + 2x + 1 = 0
(x + 1)^2 = 0
x = -1
ответ -3, -1, 1
ну замену можно сделать x^2 + 2x = t
t(t - 2) = 3
t^2 - 2t - 3 = 0 итд
