$\"\"$

The expression is $\"\"$

$\"\"$

Apply product of a sum and a difference: $\"\"$ .

$\"\"$

Rewrite as the difference of two products.

$\"\"$

Apply distributive property: $\"\"$ .

$\"\"$

The product of two same signs is positive and different signs is negative.

$\"\"$ . $\"\"$

The value of $\"\"$ .