Question 671593
{{{P(x)=2x(x^2+9)(x^2-2)}}}

{{{2x( x^4+7x^2-18)}}}						
							
{{{2x( x^4+7x^2+(49/4) -49/4-18)=0}}}


{{{2x((x^2+(7/2))^2-((49+72)/2))=0}}}


{{{(2x(x^2+(7/2))^2-(121/2))=0}}}

{{{(x^2+(7/2))^2=(121/2)}}}


take the square root

x^2+(7/2) = +-(11/2)

x^2= (11/2)-(7/2) OR (-11/2)-(7/2)

x^2=2  OR -9  

x=sqrt(2),-sqrt(2), 0,  3i