Simplify the product.

-3x (x^2 + 3x - 1)

To simplify the given product, we will need to apply the distributive property. This property states that the product of a number and an expression in parentheses can be found by multiplying the number by each term inside the parentheses.

First, let's distribute the -3x to each term inside the parentheses:

-3x(x^2) + (-3x)(3x) + (-3x)(-1)

Now, simplify each term:

-3x^3 + (-9x^2) + 3x

Finally, we can combine like terms:

-3x^3 - 9x^2 + 3x

Therefore, the simplified product is -3x^3 - 9x^2 + 3x.