Решите уравнение x^2-5|x|+6=0 и (x+2)^2+9(x+2)+20=0

1) Распадается на 2 уравнения
а) x < 0; |x| = -x
x^2 + 5x + 6 = 0
(x + 2)(x + 3) = 0
x1 = -2 < 0; x2 = -3 < 0
b) x >= 0; |x| = x
x^2 - 5x + 6 = 0
(x - 2)(x - 3) = 0
x3 = 2; x4 = 3

2) Замена x+2 = t
t^2 + 9t + 20 = 0
(t + 4)(t + 5) = 0
t1 = x + 2 = -4; x1 = -6
t2 = x + 2 = -5; x2 = -7