CHAPTER

7

Expression and

Equations

Basic Concepts

In algebra, letters are used as variables. Avariablecan assume values of

numbers. Numbers are calledconstants.

Math Note: In some cases, a letter may represent a specific con-

stant. As you will see in Chapter 9, the Greek letter pi (p) represents a

constant.

Analgebraic expressionconsists of variables, constants, operation signs,

and grouping symbols. In the algebraic expression 3x, the ‘‘3’’ is a constant

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