Evaluating Algebraic Expressions
Learning how to find the value of algebraic expressions by substituting numbers for variables.
What is Substitution?
Substitution means replacing variables with specific numbers, then calculating the result.
Key Idea: We find the value of an expression for given values of variables.
Example: If x = 5, find the value of 2x + 3
We replace x with 5: 2(5) + 3 = 10 + 3 = 13
The Basic Process
1
Write the expression
2
Replace each variable with its value
3
Calculate following order of operations
Important: Always use parentheses when substituting!
Visual: The Substitution Process
Interactive visualization — available in the full lesson