Please help with this polynomial: 2x^3-x^2-18x+9=0

2x^3-x^2)-(18x-9)=0 
x^2(2x-1)-9(2x-1)=0 
(x^2-9)(2x-1)=0 


which leads to x=1/2, or x=3, or x=-3 

:)