Answer:
[tex]3x^2(x-1)[/tex]
Step-by-step explanation:
Not sure what you mean by "solve" as this is an expression, anyhow..
Our common monomial factor is [tex]3x^{2}[/tex]
By factoring out this monomial, we get [tex](x-1)[/tex]
To prove this is the answer, we can do [tex]3x^2(x-1)[/tex] and see that they multiply to the original expression.