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Home > CC3 > Chapter 2 > Lesson 2.1.7 > Problem 2-68

2-68.

Read the Math Notes boxes in this lesson and for Lesson 2.1.5. Then examine the work below that shows one way to simplify the expression . Decide which property was used for each step.  

Expression 

What property was used?

  

 Original expression

 

 a.

 

 b.

 

 Added like terms

 

 c.

 

 Added like terms

What is the property used to rearrange parentheses with addition?

In part (b), some terms are moved. Why is this a legal move?

The answers are filled in below.

Expression

What property was used?

Original expression

(a). Associative Property of Addition

(b). Commutative Property

Added like terms

(c). Associative Property of Addition

Added like terms