# Evaluating Algebraic Expressions

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Examples, solutions, videos, worksheets, and activities to help Algebra 1 or grade 7 students learn how to evaluate algebraic expressions.

An expression in which some or all of the terms contain variables is an algebraic expression. If the values of the variables are known, we can evaluate the expression.

To evaluate an algebraic expression, substitute the value of the variables into the expression.

We can evaluate an algebraic expression for different values of the variable.
To evaluate 3x + 1 for x = −2, we substitute −2 in place of x
3(−2) + 1 = −6 + 1 = −5

Remember to use order of operations to evaluate and be careful with the minus signs.

Evaluating Algebraic Expressions
How to evaluate an algebraic expression when values are given for the variable(s)?

Examples:
Let x = -3, y = 7, z = -2
Evaluate x - 3y + 7

Let y = 2
Evaluate 9/y = 8y + 2

Let x = 3, y = -5
Evaluate 4x - 3y2

Let x = -2
Evaluate 3x3 - x2 + 2x + 9

Examples:

1. Evaluate x + 3 for x = 7
2. Evaluate x2 + x - 3 for x = 2
3. Evaluate y2 + x3 + 7 for y = 2, x = 1
4. Evaluate 5 - x2 for x = -2
5. Evaluate (3x)(5y) for x = -1, y = 2
6. Evaluate -7x2 -5 + y2 - x for x = -2, y = 4
7. Evaluate 3x2 ÷ 12 + y for x = 4, y = -7

How to Evaluate Expressions with Two Variables?

Evaluating Algebraic Expressions

How to Evaluate Expressions with One Variable?

Basic Mathematics & Algebra : Substituting Values Into an Algebraic Expression
Substituting values into an algebraic expression in mathematics is easier to do if the numbers the values represent are given ahead of time.

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