We are given:
\[
\frac{x^3}{(2x - 1)(x + 2)(x - 3)} = A + \frac{B}{2x - 1} + \frac{C}{x + 2} + \frac{D}{x - 3}
\]
To find \( A + B + C \), use the technique of:
- Matching coefficients,
- Substituting convenient values.
But since only \( A + B + C \) is asked, we can substitute convenient values or evaluate using known tools.
Alternatively, we expand the expression or use software (or compare numerators after common denominators).
After evaluation and solving (either manually or via systems), we get:
\[
A + B + C = \frac{4}{25}
\]