$\"\"$

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The expression is $\"\"$ .

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

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Partial fraction decomposition to the above expression.

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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Compare $\"\"$ terms.

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$\"\"$

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Compare constant terms.

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$\"\"$

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Divide each by $\"\"$ .

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$\"\"$

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Add equation (2) and equation (3).

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$\"\"$

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$\"\"$

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Substitute $\"\"$ in equation (3).

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$\"\"$

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Substitute $\"\"$ and $\"\"$ in equation (1).

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$\"\"$ .

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$\"\"$

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$\"\"$ .