Expressions and Variables: Simplifying Variable Expressions

-  In algebra, a variable is a letter used to stand for a number. The most common letters are .
-  An algebraic expression is an expression that contains integers, variables, and math operations such as addition, subtraction, multiplication, division, etc.
-  In an expression, we can combine “like” terms. (values with same variable and same power)

Examples:
Example 1.  Simplify.
Solution: In this expression, there are three terms: remember you cannot combine variables and numbers.

Example 2.  Simplify.
Solution: Combine “like” terms: .
Then: .

Example 3.  Simplify.
Solution: Combine like terms. Then:



Example 4.  Simplify.
Solution: Combine “like” terms: and
Then: . Write in standard form (biggest powers first):