Question

(x^2+27)^2-5(x^2+27)(x^2+3)+6(x^2+3)^2=0

Answer 1

(x^2+27)^2-5(x^2+27)(x^2+3)+6(x^2+3)^2=0

(x^2+27-3(x^2+3)) (x^2+27-2(x^2+3))=0  
(x2+27-3x2-9)(x2+27-2x2-6)=0
(-2x2+18)(-x2+21)=0     
(x2-9)(x2-21)=0
х hfdty +- 3, +- корень 21