Evaluating Variable Expressions

Algebra 1 · Axiom Academy

EXAMPLE Evaluating Variable Expressions A step-by-step guide to substituting values and simplifying. Evaluate the expression 3x + 2y - 5 when x = 4 and y = -2 . Excellent work! You've successfully evaluated the expression. Let's review the key steps: Substitution: First, we replaced each variable (`x` and `y`) with its given numerical value. Remember to use parentheses, especially with negative numbers! Multiplication: Following the order of operations (PEMDAS), we performed all multiplications before any addition or subtraction. Addition/Subtraction: Finally, we performed the remaining additions and subtractions, working from left to right, to find the single final value. This systematic process is crucial for accurately solving any algebraic expression.

This is the written version of the interactive lesson above. See the full Algebra 1 course.