18. \( 5+3 w+3-w \)

Let’s break that expression down with a dash of excitement! First, you combine like terms. You have \(5\) on its own, and for the variables, you’ve got \(3w\) and \(-w\). When you mix \(3w\) and \(-w\), you get \(2w\). So, the expression simplifies to \(5 + 2w\). Now, let's take a look at practical applications! This kind of simplification is super useful in everyday scenarios. For example, if you're budgeting and want to figure out your total expenses (like \(5\) representing a fixed cost and \(2w\) symbolizing variable costs depending on the number of items you buy), it helps to have a clear breakdown of your finances.