Question 38119
First of all, the third power of x is commonly typed as x^3.  "^" means "raised to a power".
So I believe your expression is actually 9x^3-6x^2-15x.
Now, a monomial is an expression with only one term (or type of x), such as x or x^2 or 3x or even 5.
A polynomial is actually what we have here, since it has 3 terms.
So, we can factor out the monomial 3x, and get the polynomial 3x^2-2x-5.
So 9x^3-6x^2-15x=3x(3x^2-2x-5).