$\"\"$

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The expression is $\"\"$ .

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Rewrite the expression as $\"\"$ .

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Apply sum formula : $\"\"$ .

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$\"\"$

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Substitute the values $\"\"$ .

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$\"\"$

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$\"\"$ \ \

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$\"\"$ Multiply numerator and denominator by $\"\"$ .

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$\"\"$

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$\"\"$

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The value of the expression is $\"\"$ .