Step 1: Write the given partial fraction form.
We have
\[
\frac{x^3}{(2x-1)(x+2)(x-3)}
=
A+\frac{B}{2x-1}+\frac{C}{x+2}+\frac{D}{x-3}
\]
Step 2: Isolate the coefficient \(C\).
Since \(C\) is the coefficient of
\[
\frac{1}{x+2},
\]
multiply both sides by
\[
x+2
\]
\[
(x+2)\frac{x^3}{(2x-1)(x+2)(x-3)}
=
(x+2)A+\frac{B(x+2)}{2x-1}+C+\frac{D(x+2)}{x-3}
\]
Step 3: Substitute \(x=-2\).
To eliminate all terms except \(C\), put
\[
x=-2
\]
Then,
\[
C=\left.\frac{x^3}{(2x-1)(x-3)}\right|_{x=-2}
\]
Step 4: Evaluate the numerator.
At
\[
x=-2,
\]
we get
\[
x^3=(-2)^3=-8
\]
Step 5: Evaluate the denominator.
Now,
\[
2x-1=2(-2)-1=-4-1=-5
\]
and
\[
x-3=-2-3=-5
\]
Thus,
\[
(2x-1)(x-3)=(-5)(-5)=25
\]
Step 6: Find \(C\).
Therefore,
\[
C=\frac{-8}{25}
\]
Step 7: Final conclusion.
Hence,
\[
\boxed{-\frac{8}{25}}
\]