$\"\"$

The expression is $\"\"$ .

$\"\"$ (Product of two different signs is negative)

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

$\"\"$

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

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

$\"\"$ (12 can be written as $\"\"$ )

$\"\"$ (Cancel common terms) $\"\"$

The product is $\"\"$ .