the last product is negative
To determine the sign of a product with a mixture of signs
• An even number of negative signs produces a positive value
• An odd number of negative signs produces a negative value
The first product has 2 negative signs ⇒ positive value
The second product has 2 negative signs ⇒ positive value
The third product has all positive signs ⇒ positive value
The fourth product has 3 negative signs ⇒ negative value
