Concept:
Factor denominator completely and decompose into partial fractions.
Step 1: Factor denominator.
\[
x^4-5x^2+4
\]
\[
=(x^2-1)(x^2-4)
\]
\[
=(x-1)(x+1)(x-2)(x+2)
\]
Step 2: Assume decomposition.
\[
\frac{2x^3+x-3}{(x-1)(x+1)(x-2)(x+2)}
\]
Assume
\[
=\frac{A}{x-1}
+\frac{B}{x+1}
+\frac{C}{x-2}
+\frac{D}{x+2}
\]
Step 3: Substitute values.
Put
\[
x=1
\]
\[
A=2
\]
Put
\[
x=-1
\]
\[
B=-1
\]
Put
\[
x=2
\]
\[
C=\frac54
\]
Put
\[
x=-2
\]
\[
D=\frac74
\]
Thus
\[
=
\frac2{x-1}
-\frac1{x+1}
+\frac5{4(x-2)}
+\frac7{4(x+2)}
\]
Hence
\[
\boxed{
\frac2{x-1}
+\frac5{4(x-2)}
-\frac1{x+1}
+\frac7{4(x+2)}
}
\]