The equation above is already in its simplest form. If you want to expand the brackets there's the guide below.
Step by step guide:
X(X-2)(9+2X)= 45
[tex] (x^{2} +2x) (9+2x)=45[/tex]
[tex]9x^2+2x^3+18x+4x^2=45[/tex]
[tex]9x^2+2x^3+18x+4x^2-45=0[/tex]
