как решить уравнение? (x2+2x)(x2+2x-2)=3

Ответ
x^2 + 2x = t
t*(t-2) = 3
t^2 - 2x - 3 = 0
t1 = 3
t2 = -1
=>
a) x^2 + 2x = t1
x^2 + 2x - 3 = 0
x1 = -3, x2 = +1
б) x^2 + 2x = t2
x^2 + 2x +1 = 0
(x + 1)^2 = 0
x3 = -1