\"\"

\

The expression is \"\"

\

\"\"   (Product of two same signs is positive)

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\"\"    (\"\")

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\"\"    (\"\")\"\"

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if \"\",where b,d \"\"

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\"\"

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\"\"     (Cancel common terms)

\

\"\"     (Multiply numerators: \"\")

\

\"\"         (Multiply denominators: \"\")

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\"\"

\

\"\"

\

The product is \"\".