What does it mean to evaluate an algebraic expression?

Evaluating an algebraic expression involves determining its numerical value by substituting specific values for the variables present in the expression and then simplifying it. This process allows you to see how changes in the variables affect the overall value of the expression. For example, if you have the expression (2x + 3) and you want to evaluate it for (x = 4), you would substitute (4) into the expression, resulting in (2(4) + 3 = 8 + 3 = 11). This clearly illustrates the steps involved in evaluating an expression: substitution followed by simplification to arrive at a numerical value.

The other options are related but do not accurately describe the process of evaluation. They refer to different concepts: comparing expressions, solving equations for variables, or rewriting expressions in simpler terms without focusing on the substitution and calculation process involved in evaluation.