Chapter 1 - Foundations for Algebra - 1-6 Multiplying and Dividing Real Numbers - Practice and Problem-Solving Exercises - Page 44: 78

Associative property of Multiplication

-5$\times$(m$\times$8)=($-5\times m$)$\times$8. We can see that the expression is still equivalent because the parenthesis just moved to a different set. The answer is the associative property of multiplication as it states that "the way in which three numbers are grouped when they are multiplied doesn't change the product".