\"\"

\

The expression is \"\"

\

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

\

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

\

\"\"

\

\"\"      (Cancel common terms)

\

\"\"      (Multiply numerators: \"\")

\

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

\

\"\"          (Divide: \"\")\"\"

\

The product is \"\".