Which of the following simplifies to the same expression as 4x^2 - 3x^2 + 5x - 24?

To determine which expression simplifies to the same as \( 4x^2 - 3x^2 + 5x - 24 \), we first simplify the original expression.

Starting with \( 4x^2 - 3x^2 + 5x - 24 \):
\[
4x^2 - 3x^2 = x^2
\]
So, we can rewrite the expression as:
\[
x^2 + 5x - 24
\]

Next, we will factor \( x^2 + 5x - 24 \). We need two numbers that multiply to \(-24\) and add up to \(5\). The numbers \(8\) and \(-3\) work, so we can factor the expression as:
\[
(x + 8)(x - 3)
\]

Now let's check which of the provided expressions simplifies to this:

1. \((x + 8)(x - 3)\) - We have already established that this is the correct factorization.

2. \((x + 6)(x - 4)\):
\[
= x^2 - 4x + 6x - 24 = x^2 + 2x - 24 \quad \text{(not the same)}
\]

3. \(4x(x - 6)\):
\[
= 4x^2 - 24x \quad \text{(not the same)}
\]

4. \(2(x - 12)\):
\[
= 2x - 24 \quad \text{(not the same)}
\]

The only expression that simplifies to the same as \( 4x^2 - 3x^2 + 5x - 24 \) is:
\[
\boxed{(x + 8)(x - 3)}
\]