$\"\"$

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The expression is $\"\"$ .

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If $\"\"$ , where b,d $\"\"$ .

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$\"\"$

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$\"\"$ (Multiply numerator: $\"\"$ )

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$\"\"$ (Multiply denominator: $\"\"$ )

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$\"\"$ (Divide: $\"\"$ ) $\"\"$

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The product is $\"\"$ .