$\"\"$

The expression is $\"\"$

$\"\"$

Apply square of a sum formula: $\"\"$ .

$\"\"$

Rewrite as the sum of two products.

$\"\"$

Apply distributive property: $\"\"$ .

$\"\"$

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

$\"\"$

Combine like terms.

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

The value of $\"\"$ .