Exercise 38 Page 558

The product of two negative numbers is positive.

Practice makes perfect

When multiplying or dividing a combination of positive and negative numbers, remember to watch the signs. If the signs are the same, the result will be positive. If the signs are different, the result will be negative. For the given multiplication, we have two negative and two positive. 4(-8)(5)(-1) Let's use Commutative and Associative Properties of Multiplication.

4(-8)(5)(-1)

CommutativePropMult

Commutative Property of Multiplication

4(5)(-8)(-1)

AssociativePropMult

Associative Property of Multiplication

((4)(5))((-8)(-1))

MultNegNegTwoPar

(- a)(- b)=a* b

((4)(5))(8*1)

IdPropMult

Identity Property of Multiplication