$\"\"$

The expression is $\"\"$ .

$\"\"$ (The product of two different signs is negative)

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

$\"\"$ (The product of two same signs is positive)

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

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

The product is $\"\"$ .