$\"\"$

The expression is $\"\"$ .

$\"\"$ (Substitute : $\"\"$ )

$\"\"$ (Apply associative property of multiplication: $\"\"$ )

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

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

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

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

The solution is $\"\"$ .