# Expressions and Equations / Building Expressions

Activity 3 of 18
In this lesson students focus on comparing expressions and establish a foundation for the definition of equivalent expressions.

## Planning and Resources

Objectives
Students should identify equivalent expressions and explain why they are equivalent using properties of multiplication and addition. They use a variety of strategies, including rewriting an expression and properties of operations, to develop equivalent expressions.

Vocabulary
expression
variable
constant
associative property
commutative property
distributive property
equivalent expressions

Standard:

## Lesson Snapshot

#### Understanding

Two expressions are equivalent if they have the same value for every possible replacement for the variable or variables.

### What to look for

Some statements can be true for many values of a variable or variables but not true for others. For example, “multiplication” makes things larger is true if you are multiplying whole numbers greater than 1.

### Sample Assessment

Which expression is equivalent to 8(x-2) + 4(3-x) - 2x?