The best way to see this is to multiply it back:
[tex]= x^3- 9x^2- 8x+ 16[/itex]
??? x can be any number! Did you mean "what are the values of x that make this 0" or "what values of x solve ?And what are the values of x?
In this case you can also factor so
and you can use the fact that "if ab= 0 then either a= 0 or b= 0".
What would be good study material for this type of algebra?[/QUOTE]