$\"\"$

\

The expression is $\"\"$ .

\

Rewrite the above expression as $\"\"$ .

\

Partial fraction decomposition to the above expression.

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

Compare $\"\"$ terms.

\

$\"\"$ .

\

Compare $\"\"$ terms.

\

$\"\"$

\

Compare constant terms.

\

$\"\"$

\

Add equation (1) and equation (3).

\

$\"\"$

\

Subtract equation (2) from equation (4).

\

$\"\"$

\

Substitute $\"\"$ in equation (2).

\

$\"\"$

\

Substitute $\"\"$ and $\"\"$ in equation (2).

\

$\"\"$

\

$\"\"$ .

\

$\"\"$

\

$\"\"$ .

\

Substitute $\"\"$ , $\"\"$ and $\"\"$ in the above equation.

\

$\"\"$

\

$\"\"$ .

\

Thus, $\"\"$ .

\

$\"\"$

\

$\"\"$ .