Evaluating expressions
Evaluate algebraic expressions by substituting values and using order of operations.
Objective
Evaluate algebraic expressions by substituting values and using order of operations.
What it means
Evaluating an expression means replacing each variable with its given value and simplifying using order of operations.
Key terms
- Evaluate
- To find the numerical value of an expression.
- Order of operations
- Parentheses, exponents, multiplication/division, addition/subtraction.
Rules to remember
- Substitute every variable with its given value before computing.
- Follow order of operations: parentheses, exponents, multiply/divide, add/subtract.
- Use parentheses around negative substitutions to avoid sign errors.
Step by step
- 1SubstituteReplace each variable with its value, using parentheses.
- 2SimplifyApply order of operations to compute the final value.
Common mistakes
- Forgetting parentheses around negative substitutions, causing sign errors.
- Squaring before applying a negative sign correctly.
Tips
- Always wrap substituted values in parentheses.
- Do exponents before multiplication.