Multiply,

(x^4 - 3)(2x + 1)

(x^4-3)(2x+1).

2x^5 + x^4 - 6x -3.

To multiply the given expressions, we will use the distributive property. This property states that when multiplying a term by a sum of terms, we need to distribute the term to each term in the sum and then combine like terms, if any.

Let's start by multiplying the first term, x^4, by each term in the second expression, 2x + 1.

(x^4 * 2x) + (x^4 * 1)

This simplifies to:

2x^5 + x^4

Next, let's multiply the second term, -3, by each term in the second expression, 2x + 1.

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

Simplifying this gives us:

-6x - 3

Now, let's combine the two results we obtained:

(2x^5 + x^4) + (-6x - 3)

This can be simplified further by combining like terms:

2x^5 + x^4 - 6x - 3

So, the final answer after multiplying (x^4 - 3) and (2x + 1) is 2x^5 + x^4 - 6x - 3.