SweetHaven Pre-Algebra Prime, Version 4.1

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Chapter 6—Expressions and Equations
6-2 Evaluating Algebraic Expressions

When you complete the work for this section, you should be able to:

Demonstrate your complete understanding of evaluating algebraic expressions of one and two variables.

Procedure

To evaluate an algebraic expression:

Assign a specific numerical values to all of the variables.
Complete the operations

Evaluating Expressions of Addition and Subtraction

Algebraic expressions that use addition and subtraction look like this:

x + 2 y – 4 5 + x – 8 + w

You can evaluate the expressions by giving each variable a specific numerical value and then completing the addition or subtraction..

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Examples:

Examples and Exercises

Evaluating Algebraic Expressions
of Addition and Subtraction

Use these interactive examples and exercises to strengthen your understanding and build your skills:

Evaluating Expressions of Multiplication and Division

Algebraic expressions that use multiplication and division look like this:

4a ^y/₄

You can evaluate expressions when you are given exact numerical values for the variables.

Examples:

Examples and Exercises

Evaluating Algebraic Expressions
of Multiplication and Division

Use these interactive examples and exercises to strengthen your understanding and build your skills:

Evaluating Expressions of Addition, Subtraction, Multiplication, and Division

Many algebraic expressions combine all four basic operations: addition, subtraction, multiplication and division. Here are some examples:

2x + 4

4x² + 3x – 2

These expressions might look complicated, but you can think of them as sets of instructions. Once you are given a specific value for the variables, these expressions tell you exactly what to do. Consider this example: 4x² + 3x – 2. If we let x = 5, the expression looks like this:

4x² + 3x – 2 = 4(5)² + 3(5) – 2

Now the expression is purely numerical. Doing the math:

4(5)² + 3(5) – 2 = 4 • 25 + 15 – 2
4 • 25 + 15 – 2 = 100 + 13
100 + 13 = 113

When x = 5 in the expression, 4x² + 3x – 2, the expression simplifies to 113.

Examples:

Examples and Exercises

Evaluating Algebraic Expressions

Use these interactive examples and exercises to strengthen your understanding and build your skills:

Author: David L. Heiserman
Publisher: SweetHaven Publishing Services