How to Evaluate One Variable? (+FREE Worksheet!)

Related Topics

• How to Translate Phrases into an Algebraic Statement
• How to Simplify Variable Expressions
• How to Simplify Polynomial Expressions
• How to Use the Distributive Property
• How to Evaluate Two Variables

Step by step guide to evaluating one variable

• To evaluate one variable expression, find the variable and substitute a number for that variable.
• Perform arithmetic operations.

Evaluating One Variable – Example 1:

Solve this expression when \( x=2\),  \(18 \ – \ 2x\)

Solution:

First substitute \(2\) for \(x\), then:
\(18 \ − \ 2 x=18 \ − \ 2(2)=18 \ − \ 4=14\)

Evaluating One Variable – Example 2:

Solve this expression. \(5 \ – \ 2 x ,x=\ – \ 1\)

Solution:

First substitute \(- \ 1\) for \(x\), then:
\(5 \ − \ 2 x=5 \ − \ 2 \ (- 1)=5 \ + \ 2=7\)

Evaluating One Variable – Example 3:

Solve this expression. \(12-2x ,x=-1\)

Solution:

First substitute \(-1\) for \(x\), then:
\( 12-2x=12-2(-1)=12+2=14\)

Evaluating One Variable – Example 4:

Solve this expression. \( -8+5x ,x=3\)

Solution:

First substitute \(3\) for \(x\), then:
\( -8+5x=-8+5(3)=-8+15=7\)

Exercises for Evaluating One Variable

Simplify each algebraic expression.

• \(\color{blue}{9 – x , x = 3}\)
• \(\color{blue}{x + 2, x = 5}\)
• \(\color{blue}{3x + 7, x = 6}\)
• \(\color{blue}{(– 3) + \frac{x}{4} + 2x, x = 16}\)
• \(\color{blue}{(– 2) + \frac{x}{7}, x = 21}\)
• \(\color{blue}{(– \frac{14}{x}) – 9 + 4x, x = 2}\)

Download Evaluating One Variable Expressions Worksheet

Answers

• \(\color{blue}{6}\)
• \(\color{blue}{7}\)
• \(\color{blue}{25}\)
• \(\color{blue}{33}\)
• \(\color{blue}{1}\)
• \(\color{blue}{-8}\)