(х+2)^4+5(х+2)^2-36=0

(x + 2)^4 + 5(x + 2)^2 - 36 = 0
((x + 2)^2 - 4) * ((x + 2)^2 + 9) = 0 | (x+2)^2 + 9 > 0
(x + 2)^2 - 4 = 0
(x + 2)^2 = 4
x + 2 = +-2
x = {-4, 0}