Algebra Foundations
Evaluating Expressions
Substituting values for variables to evaluate an expression.
Prerequisites
- Introduction to Variables
Substituting Values
Evaluating an expression means replacing each variable with a given number, then simplifying using the order of operations.
| x | 2x + 1 |
|---|---|
| 1 | 3 |
| 3 | 7 |
| 5 | 11 |
Graph Visualizer
Domain & range
Evaluate a point
- 2x + 1 = 1
The expression 2x + 1 plotted as a line.
What if x is negative?
Substitute the negative value directly, keeping track of the sign — e.g. for x = -2, 2x + 1 = 2(-2) + 1 = -3.
Does order matter?
Yes — always multiply before adding, following the standard order of operations.
Evaluating expressions, step by step
A short walkthrough of substitution and order of operations.
Video coming soon
References
Summary
To evaluate an expression, substitute the given value for each variable, then simplify using the order of operations.
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